So your AP® US History exam is coming. Even if you’ve studied your coursework carefully, the exam may still be pretty scary. But we’re here to help. Whether you’re just looking for a refresher to boost your confidence or need some intensive review to get up to speed, this AP® study guide can help set up the course work into an intense but manageable study plan.

A few notes before we begin:

Feel free to adapt this study plan to whatever suits you best. How you review the information and what parts of the study plan you emphasize should be tweaked to fit how you learn best. Focus on the methods and conditions that help you study best.

Make sure to eat healthy, sleep regularly, and generally take care of yourself throughout all this—especially as you get closer to the exam. Not only is this better for you in the long run, but it also helps you do well on the exam itself! Eating and sleeping well is a big part of helping our brains learn and remember new information. Use that to your advantage.

What you’ll need:

– Albert.io’s AP® US History practice questions. These will be our best tool in learning the information and practicing for the exam. It also is great for giving you feedback on your strengths and mistakes.

– A flashcard site such as Quizlet. Alternatively, you can just use regular notecards. Whichever format you like better.

– Note-taking materials—again, take your pick of paper or digital formats. Just remember that you’ll be doing a lot of review and highlighting, so pick a medium you’ll be willing to stare at for a long time.

– AP® Central Free Response Questions. Basically the questions from previous year’s tests. These will be useful in practicing some longer questions towards the end of the month, but feel free to check them out earlier to see what to expect!

– College Board’s Official US History Course Description and US History Course Overview. These are handy guides to the material, straight from the people making the exam! The overview is a quick summary of the material, while course description is more thorough—basically a guide for learning and teaching the course. This is probably what a lot of your teachers were working from. So we’re just cutting out the middleman for you here.

– You own AP® US History Textbook, or an online source of equal quality. Sometimes it helps to review this information from another source if you’re hitting a wall.

Optional (but helpful) stuff:

– Any AP-style workbooks or study guides your teacher provides, or any supplemental material you find helps your study of the main materials.

– A dictionary, be it print or online. History buffs can get a bit wordy sometimes, and you certainly don’t want to go into the exam with a bunch of knowledge you don’t know the meaning to.

Alright, are you ready? Then let’s begin:

Day 1

– Let’s start by reading the course overview. The most important part here is the list of historical thinking skills. Remembering events and people is key, but knowing how to think and talk about these events is what matters most. If you think you struggle with any of these skills in particular, take your notes with those skills in mind.

– Now let’s get to the history proper. You’ll want to go to Albert.io and try 14 of the Period 1 multiple choice questions. Try to spread out your answers across the sections and difficulty levels. Take notes on the explanations that come up after you answer, particularly ones you got wrong. As you work through questions, take note of key vocabulary that appear. Try to find at least 15 important terms.

(Note: we highly suggest you register for full access on Albert.io for this. Not only will you be able to access the high difficulty practice questions, but you will be able to see the explanation on the multiple choice questions no matter if you answered it correctly or not.)

– Now let’s begin making flashcards (either with note cards, a folded piece of paper, or online on a site such as Quizlet) from your key terms and those notes you made on the multiple choice questions. Put the name of the term on one side and on the other provide the definition and significance

Here’s an example:

Side 1: Maize

Side 2: Definition: Corn; a crop originally from the southern area of Central America that spread outward by about 1200 became an important staple of pre-Columbian life.

Significance: With a stable food source, many Native American peoples in Central America and southwestern North America were able to move away from hunter-gatherer lifestyles towards more sophisticated agrarian societies.

(Bonus Tip: If you find a key term especially hard to remember, it may help to add a small hint on Side 1 of your flashcard beneath the term itself.)

Day 2

– Take out those flashcards and quiz yourself. See how many definitions you can recall without checking the other side. If any particular definition or flashcard gives you trouble, mark that one and focus on that on later reviews.

– Now look over those notes and key terms you made. Just like with the flashcards, make a note of concepts you are having difficulty understanding, and check your textbook for clarification.

– Now let’s cover some new ground: read pages 25-28 of the AP® US History Course Description PDF. See if you can give examples for the right column of key concepts for each section. If you have any trouble thinking of examples, draw from your notes and textbook.

– Try 14 more multiple choice questions from Albert.io Period 1. Again, make sure to divide the questions across sections and difficulty levels. Also make sure to read the explanations, record key terms, and take notes on the questions you got wrong.

Day 3

– Now let’s head to the multiple choice section on Albert.io and complete 23 questions from Period 2. As always spread out your questions across sections and difficulty levels, read the explanations, collect at least 20 key terms, and take notes on the gaps in your information (this should be happening every time we do multiple choice questions on Albert.io, in case you couldn’t tell).

– Next it’s time for something new: go to the short response questions on Albert.io, and try the short response questions for Period 2. Try to answer these in a test like environment, so cut out any distractions and don’t let yourself look at your notes. Once you’re done, you should compare your answer against the rubric provided.

– Let’s wind things down by making flashcards for Period 2—draw from your new key terms, notes, and the feedback you got from the multiple choice and short response questions for this.

Day 4

– Warm up today by reviewing your notes and quiz yourself with your flashcards. Check your textbook for any information you’re still struggling with from Period 2.

– Now read pages 30-34 of the course PDF. As with the Period 1 material, try to provide specific examples for the right column of key concepts. You also want to update your notes and key terms for any new information you learned here.

– Next, let’s complete 23 more multiple choice questions from Period 2. You should be getting a sense by now for the structure and feedback system of Albert.io, so feel free to tweak how you do multiple choice to your own learning style.

– Once you’ve done that, go to the short response question section, and try the FRQ and DBQ for Period 2. These will be the most challenging kinds of questions you face on the exam, but remember that they’re just practice here.

Generally, DBQs will take longer due to the need to address the source material piece by piece, but also provide you with the evidence you need right with the question. FRQs, on the other hand, provide more freedom for their answers, but can be challenging as they require you to come to the table with the information and evidence you need.

Remember to cut out your notes and any distractions to simulate a test environment. When you’re finished, compare your notes to the rubric and make notes on any information you struggled with on the questions.

Day 5

-Complete 26 multiple choice questions from the Period 3 sections on Albert.io. Take notes and collect 20 key terms

– Our next activity is going to get a little more specific. Look up the Bill of Rights (your textbook may have it. If not you can find an online pdf here). Read through it, and consider its significance in terms of what it was reacting to. You don’t have to memorize each amendment, but try to get a sense of what it was trying to guarantee and its significance for the formation of the American system of government.

– Finally, you’ll want to make some flashcards for Period 3, based off what you learned from the today’s questions, the multiple choice questions, and the bill of rights. You should be getting a pretty sizable deck by now, which is exactly what you want.

Day 6

(Note: This is our first “weekend” day. Basically this will be double the material as a usual day, and you can choose to tackle it all in one day and have the other day free, or split it up among two days.)

– Start the day by reading pages 36-42 of the course PDF, and try to provide specific examples for the key concepts. These are the sorts of examples you’ll want to be able to pull out for FRQs and DBQs on the test, so it’s important you gain the ability to think of and provide them without your notes.

– Complete another 26 multiple choice questions on Period 3. Remember to read the explanations and take notes on questions you got wrong!

– Finish up your Period 3 course by updating your notes, flashcards, and key terms for the section. We want these to be in good shape, as we’ll be using them for the review on the second part of the day.

– If you haven’t already, take a short break (15-45 minutes). If you plan to split up your weekend courses, save the rest of the day’s material for tomorrow.

– Look back over all the notes and flashcards you’ve made for the previous three periods. This is just a quick refresher before we get into the review proper, so don’t worry about it too much or take too long here.

– Next, it’s time for a quick review! Go to the multiple choice questions and answer 8 questions from Period 1, 11 from Period 2, and 12 from Period 3. Try to get at least 2-3 questions from each section per period. Take notes on the questions you miss and pay attention to the explanations.

– Read pages 7-21 of the course PDF, which focuses on our historical thinking methods and historic themes. Think about how these methods and themes apply to the information you’ve learned in Periods 1-3. While not all the historic themes really apply in these sections, at least a few can be seen in different sections of the material.

You’ll want to go back through your notes and key terms here and mark ideas and events that are particularly relevant to particular themes of the course. You also should be familiar enough with the material by now to think historically about all the major terms and events of the three periods.

And there we have it: our first week down. Good job on keeping pace so far, but remember not the slack off. There’s still plenty of ground left to cover.

Start your AP® US History Prep today

Day 1

– We’re going to start a bit differently today. Drawing from what you’ve learned from the first three periods, make a causal timeline of the information you’ve learned so far. While you can add dates if you want, these are less important to figuring out a line of cause and effect. What matters is you establish a linear narrative of “X led to Y led to Z” or “X occurred, so Y occurred in response, while Z occurred at the same time”.

Basically, this is our “big picture” to tie together all the different periods and concepts of this AP® study guide. Try to get 15-20 major events down from each Period.

– Alright, now we’re off to Period 4. Heads up: this one will be pretty intensive. Go the multiple choice section on Albert.io and try 25 questions from Period 4. Take notes on these sections, and try to make at least 25 new key terms.

– We’ll finish out our day by making new flashcards from the key terms and other important bits of Period 4. We know this is a lot of ground to cover. Don’t let the breadth of information we’re covering here deter you. You’ll be able to handle it just fine by the end of the month.

Day 2

– Since we covered so much material yesterday, let’s start off today by reviewing your notes from the new period and briefly quizzing yourself with the flashcards. If any of these concepts give you trouble, make sure to mark them for later.

– Next, let’s try for 25 more multiple choice questions for Period 4. Don’t forget to read the explanations and take notes on the questions you got wrong.

– Now let’s check out pages 44-51 of your course PDF. See if you can provide specific examples for the right-hand column here. If you’re struggling to do so, find examples from your notes or textbook.

– We’ll finish out the day by heading back to Albert.io and answering one of the short response questions on Period 4. Remember to conduct the question in a test like environment. You’ll also want to remember to check your answer against the rubric to see what you’ve missed.

Day 3

– Still with us? Good. Let’s start out today by going back and looking over those flashcards you marked yesterday. Do you still have trouble remembering any of them? Quiz yourself (and do a little research, if necessary) until you’re comfortable with them.

– Now let’s hit up 25 more questions on Albert.io for Period 4. Follow the usual rules for spacing out which questions you choose and note taking on the explanations.

– Next, you’ll want to try to answer the remaining short answer on Albert.io for Period 4. Once you’re done, look at the rubric and compare it to your answer. If you missed any key points, consider rewriting your response, with the missing pieces in mind.

– We’ll be keeping this brief today, so finish things up here by updating your notes and key terms with whatever you learned from the questions you answered. We’re nearly done with this period, so make sure you’re confident with everything we’ve learned here.

Day 4

– Today we’re finally finishing up Period 4, so let’s do one more review of your notes and flashcards. Try to focus on anything you marked in your previous reviews as your problem areas.

– Now let’s do 25 more multiple choice questions for the period. Don’t forget to follow standard practices for spacing out your questions and taking notes on the explanations.

– Next up is Albert.io’s DBQ for section 4. Remember, DBQs are some of the most thorough questions you’ll need to give, but it also provides you with a lot of the information you need with the documents themselves. Don’t be afraid to bring any relevant outside information you have about the subject, but make sure to use the information in front of you as well.

– Pull out your causal timeline now, and add a section for the events of Period 4. Due to the crazy amount of material on Period 4, you could have as many as twice the amount of events to put down here, so expect somewhere between 25-40 events.

Day 5

– After spending the better part of our week on Period 4, it’s finally time to move on. Next, let’s go to the multiple choice section on Albert.io and complete 26 question on Period 5, across various sections and difficulty levels. Make sure to take notes, particularly for questions you missed, and try to make at least 20 key terms from the material.

– The last big thing today will be Albert.io’s FRQ for Period 5. When you’re done, check your answer against the rubric. Like we said, FRQs are pretty tricky: they may seem a lot simpler than DBQs, but because nothing is provided for you, you have to bring all the examples to prove your points yourself. Don’t worry if you struggle here, we’ll come back to it later.

– And we’ll finish out the day by making some flashcards for Period 5. Don’t hesitate to use the multiple choice questions and FRQ to gauge which parts of the period you need to sharpen your knowledge on.

Day 6

– Alright, our second weekend section. You’ll want to start your day reviewing your notes from Period 5, and quizzing yourself with those new flashcards. If you want you can include some materials from Period 4 as well.

– Next we’ll answer 26 more questions for Period 5. Make sure to space out your questions across sections and difficulty levels, and take notes on the explanations for questions you got wrong.

– Now, you’ll want to read pages 52-58 of the course PDF. Go through and try to provide specific examples for the key concepts listed, first without and then with your notes. If you had trouble on yesterday’s FRQ, review this list and use the examples there to revise your answer.

– Take a short break here, or if you’re splitting up Day 6 across both weekend days save the rest of today’s material until tomorrow.

– And we’re back for the Periods 4 and 5 review! Go to the multiple choice section of Albert.io and take 15 questions from Period 4 and 14 questions from Period 5. Try to answer at least a few questions from each section of each period.

– We’ll finish off the week by applying critical thinking to all the information we’ve learned. Go back through your notes and key terms for Periods 4 and 5 and apply the key historic themes and the methods of historic thinking from pages 7-21 of the course PDF. Could you comfortably explain to a friend how the information from these periods apply to these themes?

And there we go: two out of four weeks done, five out of nine periods covered! Find some way to celebrate making it halfway through this study plan, and enjoy the rest of your weekend!

Start your AP® US History Prep today

Day 1

– Hello again, folks. Let’s test what you know by doing 26 multiple choice questions for Period 6 on Albert.io. Make sure to space out the difficulty of these questions, and take notes on the explanations for questions you got wrong. Take careful notes on the material, and make at least 20 new key terms.

– To continue our little test, head to the short response section and choose a short answer question for Period 6. Complete the short answer in test like conditions, then compare your answer to the rubric.

– Wrap up the day by making flashcards for Period 6 from your key terms, as well as any new material you encountered from the multiple choice and short answer questions.

Day 2

– Today marks the second half of our Period 6 material. Start by reviewing your notes and quizzing yourself with your new flashcards. Make sure to keep track of any concepts or terms that give you trouble.

– Now we’ll go to Albert.io and answer 26 more multiple choice questions. Hopefully you should be pretty familiar with all the material by now, but make sure to read the explanations and take notes on anything you got wrong.

– Next open up the course PDF and read pages 60-66. As with before, go through the list of key concepts and see if you can provide specific examples of historic events, peoples, or trends for each.

– Finally, we’ll answer the second short answer question and the DBQ for Period 6 on Albert.io. Before you try the DBQ, run over the examples you just made for the course PDF. While DBQs provide a large amount of the evidence in the documents themselves, the best answers are those that bring in outside knowledge and tie it in with the documents.

Day 3

– Start the day by retrieving your causal timeline, and add 15-20 events each for Periods 5 and 6. If the timeline is getting overwhelming for you, make an abridged version from only the most important events or themes. This shouldn’t replace the longer timeline, but will be easier to look at for review.

– Now that we’ve settled that,answer 27 multiple choice questions for Period 7, across various sections and difficulty levels.Take thorough notes on the material, and create 30 new key terms from people, events, and themes of this period. Take thorough notes on the material, and create 30 new key terms from people, events, and themes of this period.

– Next, head to the short response section and answer Period 7’s short answer question. When you’re done, compare your answer against the provided rubric, and take notes on any part of the desired answer you missed.

– Now let’s finish the day by creating some flashcards for yourself for Period 7. There’s a lot of material here, so feel free to focus in on the terms and concepts you found difficult today.

Day 4

– Yesterday was pretty intensive, so let’s start today slow. Just review your notes for Period 7, and briefly quiz yourself on your new flashcards. You’ll want to mark anything that gives you special trouble.

– Next we’ll head to Albert.io and answer 27 more multiple choice questions on Period 7. As always, space out your questions across the sections and difficulty levels and take notes on the explanations of answer you got wrong.

– Now let’s read pages 68-75 of the course PDF. Take notes on any key concepts you missed, then try to provide examples for the listed key concepts.

– Last but not least we’re going to try the FRQ for Period 7 on Albert.io. Once you’ve finished, compare your answer to the rubric once you’re finished. When you’ve done this, go back to exam conditions and rewrite your answer with the rubric in mind.

Day 5

– Alright, last day for Period 7. Let’s start by reviewing our notes and key terms, particularly any new notes you added yesterday or anything you marked as giving you trouble.

– Next we’ll go to Albert.io and answer 27 more multiple choice questions. Take notes on the explanations, particularly on questions you got wrong or guessed on.

– After that, let’s answer the DBQ for Period 7 on Albert.io. Remember: the key to DBQs is to integrate the evidence in front of you with your outside expertise in US History and historical thinking skills.

– Finally, let’s pull out our full causal timeline and add a section for Period 7. As with Period 4, try to give this period double (25-40) the events of your usual for individual periods. Remember, dates are less important than establishing connection and narrative. How does one event lead to another, or how do two events affect one another?

Day 6

– Here we are, at the end of week 3. Today we’re going to start with the review, and then continue on to the beginning of Period 8. This will give us extra time to review at the end of week 4 and save us from dragging out the relatively short final two periods.

But enough forecasting. Let’s get to the review.  You’ll want to start with multiple choice: go to Albert.io and answer 13 questions from Period 6 and 13 questions from Period 7. There should still be a few questions left in each even once you’re finished.

– We’ll finish the review with a quick reflection on the historic themes and methods of historic thinking, and how the information you’ve learned for Periods 6 and 7 apply to them. You’ll want to go through your notes and mark key terms you feel are relevant to particular themes, and consider how to apply these ideas within the context of historical thinking.

– Take a short break (or even a long break, if your schedule allows it). If you plan to split up this session into two days, save the rest of the material here for Day 7.

– Welcome back! We’ll be spending the rest of the day on Period 8, so let’s head to the Albert.io multiple choice section and answer 28 questions across Period 8.Don’t forget to take thorough notes on the material and create 20 key terms from key concepts.

– Next, we’ll go to the short response section for Albert.io and answer one short response question and the DBQ for Period 8. Once you’re done, compare your answers to the rubric and take notes on concepts you missed or forgotten.

– Finally, take the time to make some flashcards from Period 8 based off of your notes and what you learned from answering the Albert.io questions. Go enjoy the rest of your weekend; we’ll be back for the final week!

Start your AP® US History Prep today

Day 1

– Ready for the home stretch? Let’s begin by quizzing yourself with your Period 8 flashcards. If you find yourself struggling with anything, you may want to mark it down for later attention.

– Next, go to Albert.io and answer 28 more multiple choice questions from Period 8. As always, space out the question distribution and take notes on the explanations.

– After that you’ll want to read pages 77-83 on the course PDF, and mark down examples for the key concepts listed. Not only is this helping you learn to connect themes with specific evidence, but it’s also preparing you for the day’s next step.

– Our last step of the day will be answering the remaining short answer and the FRQ for Period 8 on Albert.io. While you shouldn’t have your notes out while answering the questions, you should have plenty of evidence still fresh in your mind from the course PDF exercise.

Day 2

– And at last, we have the final period. Like the very first period, this one is fairly light on materials, so consider it a break between the intensive material of Periods 7 and 8 and the cumulative reviews coming at the end of the week.

As you might expect, start with the multiple choice section on Albert.io, and answer 17 questions across a variety of sections and difficulty levels. Make sure to collect key terms take notes on the explanations, particularly for questions you got incorrect or questions you answered correctly only by guessing. Since Period 9 is pretty light, you should only need ~15 terms here.

– Reaching the peak here, we’re going to try and tackle the Period 9 FRQ on Albert.io now. Once you’re finished, review the question against the rubric and then rewrite your answer with the rubric in mind.

– Lastly, we’ll cool down by making just a few more flashcards based off what you’ve learned with Period 9. Draw from your key terms, notes, the Albert.io questions, or (preferably) a combination of the three.

Day 3

– Start the day with a quick review of your notes for Period 9. Once you’re familiar with those, quiz yourself with the Period 9 flashcards. Highlight any ideas or flashcards that give you trouble.

– Now that we’ve warmed up, try to answer 17 more multiple choice questions for Period 9. Read the explanations for the answers, and take notes on the explanations of questions you got wrong.

– Next we’ll open up our course PDF, and read through pages 85-89. See if you can’t provide examples for the listed key concepts from your knowledge of the period alone.

– The last thing we’re going to do today is to update one last time our causal timeline with events from Periods 8 and 9. Add the usual amount (15-20) of events for each Period.

Day 4

– Today we’re going to have a quick review for Periods 8 and 9. You’ll want to start by quickly reviewing your notes and flashcards from the periods. Focus on any terms you’ve highlighted previously as your weaker areas of knowledge.

– Now for a brief multiple choice review on Albert.io: 15 questions from Period 8, and then 8 questions from Period 9. Follow standard procedure for which questions you choose, and on taking notes from the explanations.

– Finally, we’ll apply our concepts of historical themes and historical thinking to your knowledge of Periods 8 and 9. Tag your notes with relevant historic themes, and brainstorm for a while on how you can use the information within the modes of historical thinking.

Day 5

– Today is going to be a quick overview of all previous periods rolled into one. Just a brief check to make sure that you have everything you need before heading into the final review.

If you need to review your notes or flashcards from any Period before you begin, start with that now. Pay careful attention to those problem areas you highlighted earlier!

– Now you’ll want to review your causal timeline (and your abridged timeline, if you have one). Polish it up, fill in any gaps you find, highlight particularly important events, and clarify the links between events. This can be a powerful tool for the exam, so make sure it’s as honed and complete as you can make it.

– Now it’s time for a full review of multiple choice. Go to Albert.io and answer

– 4 questions from Period 1

– 8 from Period 2

– 9 from Period 3

– 12 from Period 4

– 10 from Period 5

– 10 from Period 6

– 10 from Period 7

– 12 from Period 8

– 4 from Period 9

That should total to 79 questions in all, which makes for a pretty tall order! Still, you should have a strong enough understanding of all this material to answer these questions confidently and relatively quickly.

Make sure to take questions you haven’t answered, and when possible space out the questions you choose among the sections of each period. (Alternatively, go to our AP® US History Ultimate Study Guide and click the links in the subject breakdown).

For this review, make sure you answer the questions in a test like environment—no distractions, no notes.

Day 6

– Here we are, final weekend! The exam may be coming up soon, but if you’ve stuck to the regiment here (or your own version), then you should be more than prepared to handle it. This weekend’s material will be a back to back final review session. You’ll want to maintain an exam like environment—no distractions, no notes. Good luck!

Let’s begin by reviewing your notes and key terms one last time. Feel free to quiz yourself on your flashcards as well.

– Now for a multiple choice review. Go to Albert.io and answer the following questions:

– 2 from Period 1

– 5 from Period 2

– 5 from Period 3

– 11 from Period 4

– 6 from Period 5

– 6 from Period 6

– 9 from Period 7

– 7 from Period 8

– 3 from Period 9

That’s a total of 54 questions. Space out the questions if you can, but make sure to only choose questions you haven’t already answered.

– Next, pull up AP® Central’s section for previous tests. We’re going to be trying a DBQ from the exam makers themselves now. Select a previous year and try to answer one of the DBQs provided. (A good one to try is 2013’s question on public opinions of slavery, but you can look around and choose one for yourself). Once you’ve finished, review your answer against the site’s scoring guidelines, and revise the essay to these standards.

– Take a break (you’ve certainly earned it). If you plan to split up the weekend session into two days, do so here.

– Alright, time for round two. Briefly review your notes, then get ready for the final wave of multiple choice:

– 2 from Period 1

– 5 from Period 2

– 5 from Period 3

– 12 from Period 4

– 6 from Period 5

– 5 from Period 6

– 9 from Period 7

– 8 from Period 8

– 2 from Period 9

Again, this should total to be 54 questions in all. With this last round, you should have finished every question from every period on the Albert.io site! Congratulations!

– Now it’s time to try another question from a previous year’s exam—this time an FRQ. Go to AP® Central, and pick a question from a previous year to answer (if you have trouble deciding, consider 2012’s question 4, from part C).  Once you’ve finished, compare your answer to the scoring guidelines for that year.

And there you have it! You have now successfully completed Albert.io’s 1 month AP® US History study plan.

In the days between the end of this AP® study guide’s course and the test, make sure to periodically review your notes, key terms, flashcards, and timeline. On the night before the exam itself, eat a healthy dinner and get plenty of sleep. On the day of the exam, have a good breakfast (ideally with lots of protein) and that you bring snacks for the test itself.

Remember to take the exam seriously, but also don’t let its importance or intimidation factor daunt you. In the end, it is just one test in one specific subject area. And if you managed to keep to this plan, you should be more than ready. We’re sure you’ll do great.

Let us know what has worked for you. What did you like best about this one month study guide? Do you have recommendations of your own on how to study for the AP® US History exam?

Start your AP® US History Prep today

Looking for AP® US History practice?

Kickstart your AP® US History prep with Albert. Start your AP® exam prep today.