Beginning in 1790 a census of the population of the United States has been taken every ten years by the federal government for the purpose of apportioning representatives to the lower house of Congress. Census schedules are essential to the family historian and researcher investigating regional and local history, immigration, naturalization, westward expansion, the status of free and slave labor, and other topics.

(Iowa territorial and state censuses supplement the federal censuses which began in Iowa in 1840 and continued every ten years. The earlier state census records are hit and miss for years and counties available and many are not filmed but are available to order in book form. While this article addresses the federal census, much of the general information in it applies equally well to the state census.)

You can learn specific information about a family from census records but the primary use of census information is to serve as a connector to other records. When you know the place of residence of a family, you then know where to look for other records such as deeds, marriages, births, deaths and wills.

The original census schedules were hand written and were microfilmed by the Bureau of the Census. The National Archives acquired the master negative microfilm rolls from the Bureau of the Census. The complete set of all existing census schedules is housed in the National Archives and Records Administration (NARA) in Washington, D.C. Without charge, the public also can research copies of census schedules in the Microfilm Research Room in the National Archives Building, which is on Pennsylvania Avenue, NW, between Seventh and Ninth Streets in Washington, DC. Films may also be rented or purchased from the NARA. (please note that only selected titles are available for rental) They also may be borrowed through the Interlibrary Program. In addition to NARA, Regional Archives Centers and many libraries have copies of census schedules on microfilm.

To accelerate research, the public may attend National Archives workshops and courses on census schedules and related records. The NARA also offers a number of free publications from the Product Sales Section (NWPS), National Archives and Records Administration, Room G9, Seventh Street and Pennsylvania Avenue, NW, Washington, DC 20408 (telephone: 202-501-5235 or 1-866-272-6272; fax 202-501-7170).

If you are unable to visit a library where census record microfilms are available, you can purchase catalogs for the federal population censuses from 1790 to 1920 and/or subject catalogs that list publications by topic and provide roll-by-roll lists of contents. The NARA catalogs of microfilm publications are also on-line. These catalogs will assist you in identifying which films may be of value to your research.

To protect the privacy of the individuals whose names appear in each schedule, population schedules are restricted for seventy-two years after the census is taken and are not available to researchers during that time. Records cannot be released to anyone except the named individuals, their heirs (on proof of death), or their legal representatives.

Population censuses are arranged by state and within each state by county; within each county by township or enumeration district; and within each district households are listed as they were taken by the enumerator as he went door to door. An index generally is necessary to find a particular record. Various individuals and organizations have completed alphabetical indexes for the 19th century censuses, generally through 1870, and these can be found in many libraries and genealogical collections. There are SOUNDEX or MIRACODE indexes for 1880 (only households with children 10 years of age or younger), 1900, 1910 (21 States only, mainly in the South), and 1930. These indexes, based on the sound of the surname, originally were prepared to assist the Census Bureau in finding records for persons who needed official proof of age from a period before all States had a uniform system of registering births. Researchers who cannot find a name in Soundex or in a commercial index may want to consult enumeration district (ED) descriptions and maps before undertaking the time-consuming task of examining all the schedules for a county or locality.

There are other kinds of federal census records which can also be of use to researchers. These include Agricultural, Industrial, and Mortality Schedules and the 1890-1906 Indian Census Cards Index.