The Underwood Typewriter Company was a manufacturer of typewriters headquartered in New York City, New York. Underwood produced what is considered the first widely successful, modern typewriter. By 1939, Underwood had produced five million machines.
The original Underwood typewriter was invented by German-American Franz X. Wagner, who showed it to entrepreneur John T. Underwood. Underwood supported Wagner and bought the company, recognising the importance of the machine. Underwood No. 1 and No. 2s, made between 1896 and 1900, had "Wagner Typewriter Co." printed on the back.
Underwood started adding addition and subtraction devices to their typewriters in about 1910.
During World War II Underwood produced M1 carbines for the war effort.
Olivetti bought a controlling interest in Underwood in 1959, and completed the merger in October 1963, becoming known in the US as Olivetti-Underwood with headquarters in New York City, and entering the electromechanical calculator business. The Underwood name last appeared on Olivetti portable typewriters produced in Spain in the 80s.