What is the federal census?

The Census was first administered by federal marshals in 1790, and it’s been taking place every 10 years ever since. In 1903, the Department of Commerce took over the operation of the Census.

The 1790 Census resulted in a nationwide population count of 3.9 million. That number included slaves counted as three-fifths of a whole person. Altogether, this population count was lower than leaders of the era — George Washington and Thomas Jefferson among them — expected. Questions of accuracy would prove to be a recurring theme. As a result, the modern decennial Censuses include procedures to check the accuracy of the count.

There have been a total of 22 censuses since the 1790 Census. These were often undertaken with very different counting methods and question wording. Most recently, Census 2010 was mailed to every home in America. Census 2010 reported a national count of 308 million people in one of the most accurate censuses to date. Since its inception, the Federal Census has had a huge impact and influence on American life.

Drawing Political boundaries

Data from the United States Census is at the very heart of American representative democracy. This has been true ever since the Census was ratified as part of the U.S. Constitution in 1788. Population data is used to set up political representation at all levels of government:

Census population counts determine how many seats in the House a state receives. Once determined, states draw their own district boundaries using Census data. In 2010, for example, Massachusetts lost a congressional seat (from 10 seats to 9), while Florida gained two (25 to 27).

Seats are drawn for state legislative and senatorial districts using Census data.

Cities and towns use Census data to draw internal political boundaries, like wards and districts.

Informing funding decisions

The richness of Census data allows the federal government to distribute funding for some of the country’s most critical social programs. Funds are directed toward those people with the greatest need. Most Census-guided funding to Massachusetts is allocated through one of the three systems below:

Formula grants are allocated to states through formulas that typically target greater funding to areas or populations with greater need. The largest example of this type is Medicaid. This program provides health insurance coverage to low-income families and individuals.

Unlike formula grants, project grants fund specific projects for fixed periods of time. These can include anything from scholarship funding to construction grants. The Head Start/Early Head Start programs are examples of this type of grant.

Direct payments are made to individuals, private firms or institutions for a particular activity or in support of a particular program. The Supplemental Nutrition Assistance Program (SNAP), is one such program.

Researchers take advantage of all Census products

Aside from the decennial Census, researchers make use of another Census Bureau product — the American Community Survey — to understand the makeup of America. From 1970 to 2000, the decennial Census included two questionnaires. The first, the short-form Census, was distributed to almost every household in America. The second was the long-form Census. The was distributed to the remaining one in six American residences that did not receive the short-form.

More complex and time consuming, the long-form Census gave researchers a more nuanced understanding of the population. It did so by asking more questions of a representative sample of the population. The long-form Census also extrapolated those answers across the United States as a whole. The questions included ones about languages spoken at home, as well as educational and employment situations (among other areas).

The 2000 Census was the last decennial Census to feature a long-form questionnaire. In 2005, those questions were moved over to its replacement, the American Community Survey. This survey, which takes place each year, allows fine-grained analysis of all Census-designated geographies. This includes the nation as a whole down to geographies as small as several City blocks.

Together, the American Community Survey and decennial Census help us understand a changing America. State and local governments use the Bureau’s data to help plan for population growth. Businesses use it to understand their local markets and to consider plans for expansion. In the nonprofit world, Census data are used to find vulnerable populations. Social scientists and pollsters use Census data to design sample methodology to better understand what the American public is thinking.

All told, Census data is used in many different ways.