How the Census Works

The Census Bureau strives to contact every person living in the United States with the Census. In order to do so, the survey must be accessible to everyone and people must be open to answering the questions included on it.

As seen below, the questions primarily address number of people in a household, their sex the U.S. census does not currently include options outside "male" and "female". From the U.S. Census Bureau website: "At the Census Bureau, the sex question wording very specifically intends to capture a person's biological sex and not gender. Ambiguity of these two concepts interferes with accurately and consistently measuring what we intend to measure--the sex composition of the population" and their race "data are based on self-identification. People may choose to report more than one race group. People of any race may be of any ethnic origin" (U.S. Census Bureau).

2010 Census Form

2010 Census Form; Source: U.S. Census Bureau

Click the picture to access an interactive 2010 Census Form.


Who is Counted?

If it isn't clear already, the answer to this question is: everyone. Every person living in the United States and its territories is of interest for the Census Bureau. Unlike other surveys that use a representative sample of the population, the Census aims to directly contact all people to create the most accurate count of the American population.

People who are not citizens or are not living in a traditional home are still counted as accurately as possible by the Census. As seen in the sample form above, the Census does not ask respondents about their immigration status. Some of these non-traditional groups counted include:

  • Non-citizens
  • Undocumented Residents
  • People experiencing homelessness
  • People in prison
  • Population Living Abroad

How the Counting Happens

Census questionnaires mailed to all U.S. households, and people will be asked to respond corresponding to their information based on a particular day in the year. Each person is counted at the location where they sleep most nights of the year in order to account for people who have moved, college students, and those who travel frequently.

A second mailing is sent if the first is not returned. However, if neither mailing is returned, a census worker visits the address to gather data. Census workers also attempt to contact the population that does not have a known address.

The collected information is kept completely confidential by the Census Bureau and cannot be disclosed for 72 years. This policy helps ensure the accuracy of the data, as some people may be hesitant to disclose some of the information if they thought other government agencies or outside parties could access their personal data.