United States Census Historical Background

Constitutional requirement. The U.S. Constitution requires a federal census for apportioning the House of Representatives and direct taxes. In accordance, the first federal census was taken in 1790 and has been repeated every ten years, always in a year ending with a zero. President Washington assigned the task of taking the 1790 census to the seventeen United States Marshalls. The first census was taken using existing civil divisions.

Increasing complexity. As time progressed, more and more questions were asked on the census forms. The early censuses showed the name of the head of house; other family members and slaves were only tallied by sex and age categories. Starting in 1850 each member of a household was named, along with that person's state or nation of birth. Starting in 1880 the birthplace of the father and mother of each individual was also listed. By 1900 questions about immigration to the United States and citizenship were added to the list.

Multiple copies. Three copies of most federal censuses were created. The local census taker first created a draft copy as he walked from house to house to question the residents. He later copied by hand a second draft for the state, and a third copy for the federal government. Copying errors often resulted in slight differences between the various copies. Only a few of the local or state copies have survived. Occasionally, large cities were enumerated twice in the same year when an under-count was suspected the first time.

Non-population schedules. At the same time as the federal population schedules were made, in some census years, additional census schedules were created. In 1820, 1850, 1860, 1870, and 1880 the manufacturers or industries were listed on a separate schedule. In 1840 and 1890 military pensioners, Union veterans, or their widows were listed. In 1850 and 1860 slave owners were listed together with the sex and age category of their slaves. For 1850, 1860, 1870, and 1880 a list of people who died in the 12 months prior to the census was made and called mortality schedules. Agricultural schedules for those same years listed information about farms. In 1900 a special American Indian schedules were filed at the end of a county's population schedules. Also look for 1880 "defective, dependent, and delinquent classes" and social statistics federal census schedules. 

Lost census records. Sometimes a page or two of a census was lost, or a town or two, or sometimes several counties, or even a census for a whole state or territory went missing. The entire United States 1890 census was destroyed except for 6,190 names. To learn about gaps and missing census records see the "Existing and lost censuses" section of each state's census Wiki page.

Indexes. The were produced in 1907-1908 in book form by the government for the 1790 census. In addition, starting in the 1930s, the government used a phonetic Soundex indexing system on the 1880, and 1900 censuses, and some of the states for the 1910, 1920, and 1930 census. These Soundex indexes were published by the W.P.A. on microfilm. Around 1967 Ronald Vern Jackson and commercial companies like Accelerated Indexing Systems (AIS) began to sell. This company combined their book indexes to create the first nationwide census indexes in AIS Microfiche Indexes of U.S. Censuses and Other Records, published in 1985. Starting about 1997 many of the earlier book census indexes were also made available online via the Internet, usually for a subscription fee. By 2009 FamilySearch Historical Record Collections began offering free statewide or nationwide census indexes on the Internet.