Census History

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1787
Article 1, Section 2 of the U.S. Constitution requires that a census of the population be conducted every 10 years so that the representatives in Congress and direct taxes might be apportioned.

1790
Federal marshals conduct the first census by going door-to-door through the 13 states plus the districts of Maine, Vermont, Kentucky, and the Southwest Territory (Tennessee). The marshals record the name of every householder and count the occupants in each house. African-American slaves are counted as three-fifths of a person, and American Indians not subject to taxation are excluded. The census is completed in 18 months at a cost of $44,000. The census counts 3.9 million people.

1810
Congress directs the federal marshals and their assistants to take “an account of the several manufacturing establishments and manufactures within their districts.”

1830
The first centrally produced and printed forms are used for collecting census data. Prior to this, marshals used sheets of paper or notebooks that they had designed themselves. The new forms include questions about disabilities.

1840
Questions on agriculture, mining, and fishing are added to the census. The number of economic and demographic questions increase from the six asked in the first census to more than 70.

1850
Congress establishes a temporary census office in the Department of the Interior. All free persons, rather than just the head of house, are recorded by name, along with their occupation and place of birth. Questions on social issues—taxation, churches, poverty, and crime—are added to the census.

1860
American Indians no longer living in tribal relations, and under state and territorial laws as citizens, are enumerated.

1868
The Fourteenth Amendment to the Constitution is ratified, ending the three-fifths counting rule for slaves.

1870
The first census in which all inhabitants are counted as whole persons. Asian Americans, collectively categorized as “Chinese,” are given their own racial classification..

1880
Professional enumerators replace the U.S. marshals and their assistants as census takers. American Indians living on reservations or in tribal relations are enumerated for the first time (however, they were not included in the apportionment count until 1940).

1890
For the first time, electric counting machines are used to tabulate census data.

1902
Congress authorizes a permanent census office that in the following year is transferred from the Interior Department to the Department of Commerce and Labor. (In 1913, when Commerce and Labor become separate departments, the U.S. Census Bureau is placed in the Department of Commerce.)

1920
The first census in which a majority of the U.S. population lives in urban areas; partly as a result, this is the only census after which congressional seats were not reapportioned among the states.

1930
Following the onset of the Great Depression, the Census Bureau develops a new separate questionnaire to measure unemployment.

1940
Statistical sampling techniques are introduced. These allow the Census Bureau to create a “long form” answered by only a subset of the population. In order to measure the effect of the Great Depression on the nation’s housing stock, the first census of housing is taken concurrently with the population census.

1950
For the first time, an electronic computer, UNIVAC I, is used to help tabulate results.

1960
In an effort to move toward self-enumeration, census forms are mailed to urban households. Residents are instructed to complete these forms and hold them for an enumerator to pick up. The Census Bureau automates the data capture process by introducing optical mark recognition equipment (called FOSDIC) to “read” microfilmed copies of questionnaires.

1970
Mail-in forms take precedence over door-to-door enumerators. For the first time, a 5 percent sample of respondents are asked to check off whether they are of Spanish or Hispanic origin or descent.

1980
Although the 1980 Census is considered one of the most accurate in recent decades, a number of states and localities file lawsuits challenging the final results.

1990
For the first time since 1940, the Census Bureau observes an increase in the estimated net undercount. Also, the mail response rate drops to 65 percent, the lowest since 1960. The Topologically Integrated Geographic Encoding and Referencing (TIGER) system unifies data collection and data tabulation geography and is a key component of the rapidly growing geographic information system (GIS) industry.

1999
The Supreme Court rules that statistical sampling cannot be used to determine the population data used for congressional apportionment. One of the principal ways in which the Census Bureau sought to use sampling in Census 2000 was by statistically adjusting the census counts to correct for net undercounts and overcounts.

2000
Including the hiring of 860,000 temporary workers, Census 2000 is the largest peacetime mobilization of resources and personnel. For the first time, the Census Bureau hires a private company to run a nationwide advertising campaign to encourage people to fill out their forms and reverses the downward trend in mail response rates since 1970.

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