While working at the John R. Keim Mills in Buffalo, New York, Knudsen introduced many innovations in the manufacture of bicycle and automobile parts. The Keim firm was bought out by Henry Ford in 1913, and Knudsen then ran assembly lines for the Ford Motor Company from 1913 to 1921. Following a dispute with Henry Ford, he was hired by the Chevrolet division of General Motors in 1922, and by 1927, Chevrolet outpaced Ford in sales. He became president of General Motors in 1937 and achieved international renown as a mass-production manager.
In May 1940, Knudsen resigned his position at General Motors to serve on the National Defense Advisory Commission appointed by President Franklin D. Roosevelt. He was instrumental in convincing American automobile manufacturers to take up the wartime manufacture of military aircraft. On 7 January 1941, he became director general for production in the newly created Office of Production Management and was involved in expediting U.S. war manufacturing efforts.
By a presidential executive order of 16 January 1942, the War Production Board headed by Donald M. Nelson superseded the Office of Production Management, and on 28 January 1942, Knudsen accepted a wartime commission as a lieutenant general in the U.S. Army; he served as director of production for the War Department until June 1945. He settled labor disputes and expedited the manufacture of war matériel, especially aircraft, and became known as a master troubleshooter. Knudsen was twice awarded the Distinguished Service Medal for his contributions to the war effort. After the war, Knudsen served for a time on the General Motors board of directors and also worked for the Hupp Corporation. He died in Detroit, Michigan, on 27 April 1948.
Charles R. Shrader
Beasley, Norman. Knudsen: A Biography. New York: McGraw-Hill, 1947.; Flink, James J. "Knudsen, William Signius." In John A. Garraty and Mark C. Carnes, eds., American National Biography, vol. 12, 843–844. New York: Oxford University Press, 1999.; Nelson, Donald M. Arsenal of Democracy: The Story of American War Production. New York: Harcourt, Brace, 1946.