[4] The majority of the data came from correspondence with officials of institutions providing care and treatment of certain members of the population.

Experts and special agents also were employed to collect data on valuation, taxation, and indebtedness; religion and libraries; colleges, academies, and schools; newspapers and periodicals, and wages.

[4] Special agents were also charged with collecting data on specific industries throughout the country, and included the manufactures of iron and steel; cotton, woolen, and worsted goods; silk and silk goods; chemical products and salt; coke and glass; shipbuilding; and all aspects of fisheries and mining, including the production of coal and petroleum.

Aggregate data for small areas, together with compatible cartographic boundary files, can be downloaded from the National Historical Geographic Information System.

The results from the census were used to determine the apportionment for the 48th, 49th, 50th, 51st, and 52nd sessions of the United States Congress.