Censuses had been taken prior to the Constitution's ratification; in the early 1600s, a census was taken in Virginia, and people were counted in nearly all of the British colonies that became the United States.
Down through the years, the Nation's needs and interests became more complex. This meant that there had to be statistics to help people understand what was happening and have a basis for planning. The content of the decennial census changed accordingly. In 1810 the first inquiry on manufactures, quantity and value of products; in 1840 on fisheries were added, and in 1850, the census included inquiries on social issues, such as taxation, churches, pauperism, and crime. The censuses also spread geographically, to new States and Territories added to the Union, as well as to other areas under U.S. sovereignty or jurisdiction. There were so many more inquiries of all kinds in the censuses of 1880 and 1890 that almost a full decade was needed to publish all the results.
For the first five censuses (1790-1840) enumerators recorded only the names of the heads of household and did a general demographic accounting of the remaining members of the household. Beginning in 1850, all members of the household were named by the enumerator. The first slave schedules were done in 1850, with the second (and last) in 1860. The 1890 census records were burned in a fire in the Commerce Department building on January 10, 1921. The only remaining element of the 1890 census is a special schedule enumerating veterans and their widows, which was preserved because it was in the care of another government department at the time. Census records are not available to the public until 72 years after they were taken. Every census up to 1930 is currently available to the public and can be viewed on microfilm released by the National Archives and Records Administration, the official keeper of old federal census records. The 1940 census will be available for review in 2012.
The official census-taking organ of the United States government is the Census bureau. The Census Bureau is headed by a Director, assisted by a Deputy Director and an Executive Staff composed of the associate directors. The Bureau has 12 regional offices with additional processing centers set up temporarily for the decennial censuses.
The sole purpose of the censuses and surveys is to secure general statistical information. Replies are obtained from individuals and establishments only to enable the compilation of such general statistics. The confidentiality of these replies is very important. By law, no one — neither the census takers nor any other Census Bureau employee — is permitted to reveal identifiable information about any person, household, or business. However, for extremely small villages this is done anyway, see below.
Which is not to say it has not happened. Census information was used to locate Japanese-Americans to be put in internment camps during World War II. Events like this and a general distrust of government by most Americans has hampered the Census Bureau's task in recent years.
Some states also conduct statewide censuses as the need arises.
Even for villages with a total population of zero, one or two, data are published, see List of places with fewer than ten people.