A project to develop a sequential and cumulative social studies curriculum for able students in grades 9-12 was carried out by Carnegie-Mellon University in partnership with the Pittsburgh Public Schools. The general goal of the curriculum--to help each student develop to the limit of his ability into an independent thinker and an informed, responsible citizen--was divided into four subgroups: attitudes, values, inquiry skills, and knowledge. The courses prepared were "Comparative Political Systems and Comparative Economic Systems" (9th grade), "The Shaping of Western Society and Studies of the non-Western World" (10th grade), "The American Experience" (11th grade), and "An Introduction to the Behavioral Sciences and the Humanities in Three Cities: Ancient Athens, Renaissance Florence, and Modern New York" (12th grade). A book of readings, an audiovisual kit, a teacher's manual, and an examination program were developed for each course. Two books and 12 films were completed to explain, to teachers, the curriculum and methods of using it. The results from testing the curriculum in the Pittsburgh Public Schools indicated that students in experimental-curriculum classes made significantly greater gains than did those in control classes. (LH)