This brief provides historical context to explain what motivated the development and fielding of the 2019 NSECE and the COVID-19 Longitudinal Follow-up surveys. We identify four sets of factors that made gathering nationally representative data at multiple timepoints extremely important: (1) policy developments; (2) demographic changes in the United States; (3) emerging research findings and new research questions; and (4) the identification of needed methodological improvements. (author abstract)