All observations are July 1 of each year.
This series is calculated by FRB-St. Louis using data from the Census Bureau. The FRB-Richmond District includes all of Maryland, North Carolina, South Carolina, Virginia, most of West Virginia and the District of Columbia.
Source: US. Bureau of the Census
US. Bureau of the Census, Resident Population in FRB-Richmond District [D5POP], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/D5POP/, November 25, 2015.