This federally-funded professional development program in social studies will serve grade 4, 5, 7, 8, and 11 social studies and special education teachers in New York City School Districts 31, 19, 20, 21, and 23 (hereafter District 31 Consortium) who are teaching in Collaborative Team Teaching (CTT) and inclusion classroom settings. The program provides (1) four School Year Seminars where CUNY historians will introduce participants to major U.S. History topics; (2) a week-long Summer Institute at CUNY in which historians lead participants in the study of two additional topics in U.S. History, and teachers also develop classroom activities on those topics; (3) school-year classroom visiting where teachers carry out and refine their activities; (4) monthly after-school focus groups devoted to pedagogical approaches and shared teaching experiences; and (5) pre- and post-project evaluation data that will help the teachers and the districts improve instructional practice, teacher knowledge, student achievement, and assessment-based curriculum design. Activities created by participating teachers will be made available online, and participants will be trained to present workshops at district-wide and school-site meetings.