: Analyze the prompt. Each long essay question will ask you to “rate the extent” of a certain factor in American history. Since you are evaluating, you will need to develop an argument that: Benefits: Robust digital resources complement printed materials. Cons: Less detail and depth than some guides on this list. Ideal for: One-year study aid to supplement the course manual. Our Rating: 4.5, Steps to: AP US History has some of the best digital resources of any book on this list. It's a solid guide overall, and combined,