Herman Hollerith (February 29, 1860 – November 17, 1929) was a German-American statistician, inventor, and businessman who developed an electromechanical tabulating machine for punched cards to assist in summarizing information and, later, in accounting.

His invention of the punched card tabulating machine, patented in 1884, marks the beginning of the era of mechanized binary code and semiautomatic data processing systems, and his concept dominated that landscape for nearly a century.

[1][8] In 1882, Hollerith joined the Massachusetts Institute of Technology where he taught mechanical engineering and conducted his first experiments with punched cards.

[9] At the suggestion of John Shaw Billings, Hollerith developed a mechanism using electrical connections to increment a counter, recording information.

[12] On January 8, 1889, Hollerith was issued U.S. Patent 395,782,[13] claim 2 of which reads: The herein-described method of compiling statistics, which consists in recording separate statistical items pertaining to the individual by holes or combinations of holes punched in sheets of electrically non-conducting material, and bearing a specific relation to each other and to a standard, and then counting or tallying such statistical items separately or in combination by means of mechanical counters operated by electro-magnets the circuits through which are controlled by the perforated sheets, substantially as and for the purpose set forth.Hollerith had left teaching and began working for the United States Census Bureau in the year he filed his first patent application.

Hollerith's machines were used for censuses in England & Wales, Italy, Germany, Russia, Austria, Canada, France, Norway, Puerto Rico, Cuba, and the Philippines, and again in the 1900 U.S.

These inventions were among the foundations of the data processing industry, and Hollerith's punched cards (later used for computer input/output) continued in use for almost a century.