Making Sense of the Census

Census Day is the “official day” on which the census is taken.

The first US Federal Census was taken in 1790, with the original 13 states included. The US Constitution specifies that censuses are taken every ten years and are, among other purposes, used to determine representation in Congress.

Up through 1840, federal census records named only the head of the household, but not other members. Starting in 1850, all members were named, along with their ages. Starting in 1860, the relationships (wife, daughter or son and so on), were included.

1820 and 1830 censuses included foreigners not naturalized.

The 1890 census was lost due to a fire in Washington DC. Only fragments remain from it.

1900 census included birth month and year, how many years a couple had been married, number of children and how many remained alive. 1900 and later included the year of immigration.

1920 census included the year of naturalization for foreign born people.

The most recent US Federal Census released to the public was the 1940 Census. By law, censuses are released 72 years after they are taken.

Census Day

• 1790    August 2
• 1800    August 4
• 1810    August 6
• 1820    August 7
• 1830    June 1
• 1840    June 1
• 1850    June 1
• 1860    June 1
• 1870    June 1
• 1880    June 1
• 1890    June 1 (this was a Sunday, so census-taking began June 2)
• 1900    June 1
• 1910    April 15
• 1920    January 1
• 1930    April 1 (October 1 in Alaska)
• 1940    April 1