The complete 1940 population census is online through the National Archives.
South Carolina Census Data (Microfilm)
Census schedules provide information on the people living in a household at the time of the census. Data may include: name of head of household, names, ages, gender, and race of inhabitents, along with property values.
Online is 1907 printed copy. Original handwritten census is on Microfilm HA 201 .S6 1790 Complete census tables for First Census, 1790, except for the files for six states that were burned up in the War of 1812.
Microfilm Reel 853--Georgetown and Greenville counties. Reel 854-- Horry, Kershaw, and Lancaster counties. Roll 854, Horry County, South Carolina, original returns of the assistant marshals, white and free colored population.
Microfilm Cabinets 2nd Floor ; HA201 .S6 1890. Most of the 1890 population schedules were so badly damaged by fire in January 1921 that they were disposed of. Only a few schedules still exist; South Carolina is not included in the microfilm.