The National Longitudinal Survey of Public Health Systems has followed a nationally-representative cohort of U.S. communities since 1998 to measure the scope of public health activities implemented in each community and the range of organizations and sectors that contribute to each activity. With 16 years of follow-up observations, this survey allows us to study the effects of demographic, economic, and policy shocks on public health delivery systems, and estimate the health effects attributable to delivery system change.