At the request of the Office of Curriculum and Instructional Programs, the Office of Shared Accountability examined the impact of offering Advanced Grade 8 U.S. History on enrollment and performance in Advanced Placement (AP) social studies courses in Grade 9. The study compared Grade 9 enrollment and performance in AP U.S. History or AP U.S. Government with National, State, and Local (NSL) Government for students who took Advanced Grade 8 U.S. History from 2009-2010 to 2011-2012 with peers who did not. The goal of Advanced Grade 8 U.S. History was to increase student enrollment and academic achievement in AP courses in high school in terms of both diversity and overall number of test takers with a view that access to rigorous instruction has profound implications for closing the academic achievement gaps and increasing college and career readiness for all students. The study was guided by the following questions: (1) Did enrollment in an AP social studies course in Grade 9 increase over time following implementation of the Advanced Grade 8 U.S. History course in all middle schools? a. Were students who took Advanced Grade 8 U.S. History more likely to enroll in AP social studies courses in Grade 9 than students who took on-level Grade 8 U.S. History?; and b. Besides taking Advanced Grade 8 U.S. History, what other explanatory factors were associated with enrollment in AP social studies courses in Grade 9?; (2) How did students who took Advanced Grade 8 U.S. History perform on AP social studies exams in Grade 9 compared with students without Advanced Grade 8 U.S. History? What other explanatory factors were associated with performance in AP social studies courses in Grade 9?; and (3) How does participation and performance in AP social studies courses in Grade 9 for Black or African American and Hispanic/Latino students who took Advanced Grade 8 U.S. History compare with their peers without Advanced Grade 8 U.S. History? This study provided a number of insights into AP social studies in Grade 9 for all students as well as for Black or African American and Hispanic/Latino students. More students took and earned a college-ready score in AP social studies after Advanced Grade 8 U.S. History was implemented in all middle schools. That is a positive outcome. This makes the stable rates of enrollment in AP social studies for three consecutive years of Grade 9 students very puzzling because the dramatic increase in students with Advanced Grade 8 U.S. History was intended to yield AP-ready students. This suggests that offering Advanced Grade 8 U.S. History to a majority of Grade 8 students was insufficient in and of itself to boost enrollment in AP social studies courses in Grade 9. Examining additional factors accounting for the stable enrollments in AP social studies in Grade 9 may be an important next step. [Tables are appended.]