Operational innovations have improved the Census Bureau’s efficiencies as its data-gathering duties have expanded over 230 years

1790

U.S. marshals conduct census from 1790 to 1870, using pen and paper for tabulations.

1830

Uniform, printed schedules are provided for data collection.

1854

The first map appears in a census publication.

1872

Bureau administrator Charles Seaton invents a mechanical tallying machine to speed tabulation of census data.

1874

The first “Statistical Atlas of the United States” is published. Subsequent versions are published periodically through 1920, but not again until 2007.

1880

Specially trained supervisors and enumerators replace marshals to collect census data.

1890

While working for the Census Bureau, inventor Herman Hollerith introduces an electromechanical punched card tabulator that reduces the time required to process decennial census data.

1910

The first census tracts created for a U.S. city (New York City) showing neighborhood blocks where residents generally share population characteristics, economic status and living conditions.

1940

Five percent of questionnaires include additional questions in the first use of decennial census statistical sampling.

The Census Bureau starts publishing detailed population and housing data for cities with 50,000 or more inhabitants.

1951

The Census Bureau receives UNIVAC I, the world’s first, large-scale, electronic computer for nonmilitary use. It processes 4,000 items per minute for the 1950 decennial census tabulation. Subsequent advances in computer technology boost the rate to 1 million per minute as of the 2010 census.

1958

A former army quartermaster depot in Jeffersonville, Ind., is converted into a data processing center for the Census Bureau. Today’s expanded facility includes 11 buildings with more than 1 million square feet, more than 3,100 computers and a flexible workforce of 1,200 to 6,000 employees.

1960

Populations in urban areas receive questionnaires by mail before enumerators visit.

The Census Bureau’s Film Optical Sensing Device for Input to Computers (FOSDIC), created in 1953, replaces punch cards for tabulations in the 1960 census. After high-speed cameras microfilm questionnaires, FOSDIC reads the dot-filled answers onto a computer tape.

1967-68

Dual Independent Map Encoding (DIME) is developed to enable computerized geography.

Circa 1975

All data products are available on magnetic computer tape.

1980

Ninety-five percent of U.S. households receive mail-out/mail-back questionnaires.

CENDATA, an online data service, provides limited statistical data to public. It is later replaced by American FactFinder, an online, self-service tool that searches and provides population, economic, geographic and housing information.

1990

Topologically Integrated Geographic Encoding and Referencing (TIGER), a new digital mapping and geographic referencing system, replaces DIME, creating a digital geographic database of the nation.

1997

CD-ROMs containing census data are released for public access.

2000

FOSDIC is replaced with optical character recognition technology that helps capture write-in responses electronically.

2005

American Community Survey, an ongoing program providing annual and 5-year estimates on social, demographic, economic and housing categories, replaces so-called “long form” questionnaire sent to a small percentage of American population for the decennial census.

2015-19

A new Block Assessment, Research and Classification (BARCA) software program compares satellite images of housing changes over time during in-office address canvassing to verify nearly 70% of addresses prior to the 2020 census, dramatically reducing the number of employees needed to verify addresses in person.

2019

American FactFinder ceases data collection, as the web portal data.census.gov is launched. The new centralized platform, with its simplified search tools, makes it easier for the general public to access data.

2020

The first internet self-response questionnaire for the decennial census allows access via securely encrypted application by mobile devices or desktop computers. A phone call-in center also accepts responses. Both options support responses in 13 languages.

The Census Bureau partners with Microsoft for cybersecurity training support, with Google to secure online responses with reCAPCHA verification tool, and with Apple to equip enumerators with iPhone 8s that provide additional encryption, and navigational and administrative efficiencies during field operations.