History

Innovations FAQs

Does the U.S. Census Bureau still use punch cards to process census data?

Computers replaced punch cards at the Census Bureau as computers and magnetic computer tape were introduced in the 1950s. Today, the agency uses optical character and optical mark recognition software to process census and survey questionnaires. For more information, visit the Tabulation and Processing Web page.

Soon after the Census Bureau's first use of punch cards in 1890, its employees began improving
the technology to speed processing. Above, Census Bureau technicians are building sorters to
process the thousands of punch cards a survey or census generates in the 1940s.