Advanced Placement (AP), which enables high school students to take introductory college-level courses, is the nation's oldest example of a rigorous, common curriculum. Students who score well on AP exams are more likely to persist in college and earn a degree. The Advanced Placement Expansion project of the National Governors Association Center for Best Practices (NGA Center) was one component of a large-scale initiative launched in 2005 to redesign the American high school. Alabama, Georgia, Kentucky, Maine, Nevada, and Wisconsin received funding to expand Advanced Placement (AP) courses to minority and low-income students at 51 pilot high schools in rural and urban school districts. The NGA Center, working in partnership with the College Board, has demonstrated that it is possible for states to raise rigor and get results at scale. Nationwide, the potential for AP expansion is considerable. Hundreds of thousands of students have the ability, but lack the opportunity, to take and succeed in AP courses. Governors interested in increasing this opportunity can start by setting new goals for Advanced Placement, so one-third of all high school students take an AP course and one-quarter of them score at mastery. Pursuing the strategies presented in this report and setting these goals would enable states to grow Advanced Placement courses to serve as many as 1 million students by the class of 2014. (Contains 3 tables, 2 figures, and 28 notes.) [Funding for this report was supported by the Michael and Susan Dell Foundation.]