High school social studies teachers play an important role in fostering the civic knowledge, skills, and dispositions that students need to thrive after graduation. These efforts can also help counter Truth Decay--the diminishing role of facts and analysis in American public life. Although several factors, such as state standards and assessments, influence public-school teachers' decisions about what civic content to cover, individual teachers typically have some degree of autonomy over what happens in the classroom. Given the lack of consensus about how schools should promote civic development, it is valuable to hear from social studies teachers themselves about what aspects of civic development they prioritize and how their views on the subject have changed over the past decade as societal factors (e.g., the media landscape, political polarization) have changed. This Data Note, one in a series, draws on a 2010 American Enterprise Institute report and 2019 data from RAND's American Teacher Panel to describe changes in high school social studies teachers' perspectives regarding the importance of teaching various topics related to students' civic development, their confidence that students would learn these topics before high school graduation, and their perspectives on the role of social studies instruction more generally. [This work is part of RAND's Countering Truth Decay initiative (Kavanagh and Rich, 2018) and the AEP (American Educator Panel) Civic Education Data Note series. For the 2010 report, "High Schools, Civics and Citizenship: What Social Studies Teachers Think and Do," see ED516497. For the 2019 report, "Teacher and Principal Perspectives on Social and Emotional Learning in America's Schools: Findings from the American Educator Panels. Research Report. RR-2991-BMGF," see ED609440.]