The decennial census and the data that are collected through the census and the American Community Survey play a crucial role in American society and democracy. The Census Seminar Series provides a foundational framework for understanding what the Census and the ACS are and how they interplay with many aspects of American society, such as civil rights issues, federal funding, and the role of Congress and other government agencies. With the support of subject matter experts, we developed these training modules to help community-based organizations, community advocates, and anyone interested in learning more about the Census and ACS, and how they are integral to our democracy.