The United States Census is mandated by the U.S. Constitution. The first census taken was in 1790 and the census is retaken every 10 years. The information collected varied with each census depending on the needs of the Federal Government. From 1790 to 1840, only heads of households were listed by name. Beginning with the 1850 census, all members of a household were listed.
The 1790 to 1940 censuses are currently available to the public. The 1950 United States Census is scheduled to be released on April 1, 2022. Please see the National Archives site for more information about availability of the 1950 census records.
All of the National Archives microfilm publications relating to Pennsylvania, including the federal population census 1790-1930 (except for 1890 which was destroyed by fire in 1921) are in the collection. The 1940 census is only available online. Except for 1870 there is a name index for each of the Pennsylvania population census schedules. Book indexes list the heads of families from 1790 through 1860. For 1870, only portions of the Pennsylvania census have been indexed. The 1880 Soundex Index includes only households with children aged ten years and younger but the 1900 Soundex Index and the 1910 Miracode Index include all heads of families.
Search the State Library catalog.
Search the 1940 Census online.
Information found in census records can be used to locate other records about an individual. The National Archives has several pages listing the genealogical clues that can be found in records for each census.
Soundex is a coded index based on the way a surname (last name) sounds instead of the way it is spelled. Using the Soundex system makes it easier to locate a name that has been spelled in a variety of ways.
The Rootsweb Soundex converter tool will convert a surname to its corresponding Soundex code.
During the 1850, 1860, 1870 and 1880 censuses, information was collected for special nonpopulation census schedules in addition to the population schedules. Agricultural, Industry and Manufacturing, Mortality, Slave and Delinquent, Defective and Dependent Classes schedules were completed during this period.
The federal mortality schedules for Pennsylvania, 1850-1880 and book indexes for 1850, 1860 and 1870 are in the State Library collection. The mortality schedules list persons who died within one year preceding June 1 of 1850, 1860, 1870 or 1880. Cause of death is frequently recorded.
Census records are available through several electronic databases. Family Search is a free database that includes census records. Ancestry Library Edition is available for onsite use at the State Library. Current Commonwealth of Pennsylvania employees can access HeritageQuest to search census records remotely with their State Library of PA library card by visiting the State Library's Electronic Resources Guide.