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Hollerith Census Machine
Gift of Digital Equipment Corporation, XD231.81
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Herman Hollerith, 1860-1929
Credit: US Bureau of the Census

Hollerith Census Machine
1889
Department of the Census, United States

Herman Hollerith invented the first automated tabulating system using punch cards. Initially designed to process the 1890 US census, his system became the basis for punch card accounting machines for most of the twentieth century. Hollerith became wealthy as his Tabulating Machine Company expanded beyond government customers to include railroads, insurance companies, and manufacturers.

Hollerith sold his patent rights in 1911 to a holding company (C-T-R) that was renamed International Business Machines Corporation (IBM) in 1924. Throughout most of the twentieth century punch card machines grew very sophisticated and bridged the gap between the paper and electronic ages.

Hollerith's Machine and the 1890 Census
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A pantograph punch
Credit: Computer History Museum

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Press used to read information
Credit: Computer History Museum

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The sorter had 26 slots
Credit: Computer History Museum

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Census taker interviewing
Credit: Bureau of the Census

The 1890 US census had not only to count a record number of Americans, but also collect more facts about them. Hollerith machines provided the automation that allowed the census to be completed in less than three years, compared to seven years for the previous one.

Information about each person was punched into a card using a “pantograph” punch. To read the information, the card was placed in a press where spring-loaded contacts poked through the holes, completing an electrical circuit and advancing one or more of 40 counters. The counters were recorded and reset to zero at the end of the day.

Lids on a sorting box were triggered so that cards could be sorted. A clerk could now tabulate 7,000 records a day, which was a tenfold improvement.

With 50 Hollerith machines in use, the population count(62,979,766) was reached in only three months and the full tabulation was finished two-and-half years later. Hollerith’s system saved the government $5,000,000 and tabulated all the collected information for the first time.