The AP US History Exam typically lasts for 2 hours and 15 minutes. This duration includes both the multiple-choice section and the free-response section. The multiple-choice section lasts for 1 hour and 30 minutes, while the free-response section lasts for 45 minutes. This format allows students to demonstrate their knowledge and understanding of American history through a combination of objective and subjective questions.

The length of the exam is designed to provide a comprehensive assessment of students' historical knowledge and analytical skills. The multiple-choice section covers a wide range of historical topics and periods, ensuring that students have a strong grasp of the overall content. The free-response section, on the other hand, requires students to apply their knowledge to analyze and interpret historical documents and events. This section is particularly challenging and accounts for a significant portion of the exam's total score.

According to the College Board, the AP US History Exam is structured to reflect the expectations of college-level history courses. The exam is designed to test students' ability to:

1. Understand historical concepts and terms.

2. Analyze and interpret historical documents and sources.

3. Evaluate and synthesize historical information.

4. Write coherent and persuasive essays.

The exam's duration is a balance between ensuring thorough coverage of the curriculum and allowing students to demonstrate their abilities within a reasonable timeframe. The College Board's data indicates that the current format of the exam has been effective in assessing students' readiness for college-level history courses.