Hollerith graduated from Columbia University, New York and joined the US Census Bureau as a statistician where he used a punched card device (inspired by the system used by the railroad conductors, which used punching holes in various places on a passenger's ticket to identify the holder's gender, age group, etc.) to help analyse the 1890 US census data. This evolved, in 1928, into a punched card system that stored data in 80 columns. This "80-column" concept has carried forward in various forms into modern applications.

On January 8, 1889 Hollerith received a patent for his electric tabulating machine. In 1896, Hollerith founded the Tabulating Machine Company to exploit his invention and in 1924 his firm became part of IBM. The Hollerith system was used for the 1911 UK census.