The Census and the Hollerith Machine. Constitution mandates a census, or headcount, of the country's population every ten years.

When the Constitution was written, the main reason for the census was to know the number of persons in each state. Seats in the House of Representatives could then be assigned to the various states according to their population size.

Dot-com bubble - Wikipedia

The census is still used for this purpose today. The first results from the census, which are due to be released at the end of , will be the state population totals. These numbers will be used to "re-apportion" the seats in the House. Beyond the need to know the number of people in each state, the census came to be used for other purposes.

By adding more questions, it was possible to find out many important facts about the United States and how it had changed since the last census. By , both the American population and the number of questions on the census had grown enormously.

The census had taken almost ten years to tabulate by hand. It was clear that hand-tabulation of the census would take until well past the year A resolution to this problem was presented by Herman Hollerith. He developed a machine that could read data from paper cards. Census personnel entered the data by punching out the holes on the cards. The machines could then tabulate the data very quickly.

Hollerith's machine had a long, illustrious history. When computers were widely adopted in the s and s, data was entered in the computers with decks of punched cards. This continued into the s.

First Measured Century: Interview: Alan Brinkley

Hollerith himself was one of the founders of a company called IBM - International Business Machines. Punched cards were recently famous again in the Florida vote in the presidential election in Much controversy surrounded the issue of "chads" - the little bits of punched-out paper that Hollerith showed could carry data.

Program Segment 1 Census. The Census and the Hollerith Machine - The U. Courtesy of the Library of Congress. PBS Program Trends of the Century Viewer's Voices Interactivity Teacher's Guide.