For more than two centuries, postal workers have helped the government complete the once-a-decade national census.
It’s no wonder: USPS has a duty to deliver to every household in the nation, so helping to count everyone who lives here is a natural fit.
For the first survey in 1790, U.S. marshals did the counting, but the results helped then-Postmaster General Timothy Pickering evaluate requests for new mail routes for the country’s 15-year-old mail delivery system.
When trained enumerators took over census duties in 1880, Postmasters in some rural areas received temporary census appointments. They were considered trusted federal employees with good record-keeping skills who were familiar with their communities.
In 1960, the Census Bureau relied heavily on the Post Office Department to execute the census. That year, the bureau mailed every U.S. household a preliminary census questionnaire, which enumerators later collected.
In 1980, the Postal Service delivered mail-back census forms to about 90 percent of U.S. households — more than 100 million questionnaires — with a return rate of 83 percent.
In preparation for the 1990 census, letter carriers verified each address on their routes — 88.5 million in total. To speed up delivery of mailed-back returns, USPS assigned a unique ZIP+4 Code for each Census Bureau office and assigned liaisons at each sorting facility.
Under a 1994 law, the Postal Service shared all of its delivery point addresses with the Census Bureau. This let information be shared with local and state governments, enabling a continuously updated list of addresses that could take part in census surveys.
In 2020, USPS delivered more than 590 million census-related mailpieces — one of the largest First-Class Mail mailings in a 90-day period in postal history.
The spirit of innovative cooperation between the Census Bureau and USPS has continued: This year, for the first time, respondents had the option to complete the survey online — a method made easier by the Postal Service’s Informed Delivery feature.