William Sebastian Jacobsen (January 15, 1887 - April 10, 1955) was a U.S. Representative from Iowa, son of Bernhard Martin Jacobsen. Born in Clinton, Iowa, Jacobsen attended the public schools and the Normal College of American Gymnastics Union, Indianapolis, Indiana. He served as director of physical education of the Turner Society and Y.M.C.A., Clinton, Iowa from 1910 to 1915. Manager and part owner of a mercantile store in Clinton, Iowa from 1915 to 1927. Secretary, treasurer, manager, and organizer of Clinton Thrift Co. from 1927 to 1937. Also manager of business property and farm interests. He served as delegate to Democratic State conventions 1932-1944. He served as delegate to the Democratic National Conventions in 1936 and 1944. Jacobsen was elected as a Democrat to the Seventy-fifth, Seventy-sixth, and Seventy-seventh Congresses (January 3, 1937-January 3, 1943). He was an unsuccessful candidate for reelection in 1942 to the Seventy-eighth Congress. Liaison officer, War Assets Administration, Washington, D.C., July 1945 to January 1947. Acting postmaster, Clinton, Iowa, August 1, 1951, to January 1954. He died in Dubuque, Iowa, April 10, 1955. He was interred in Springdale Cemetery, Clinton, Iowa.
