William Dewey Foster, AIA, earned bachelor and master of science at the Massachusetts Institute of Technology and was a draftsman in several New York architectural firms before his service in World War I with the U.S. Army 40th Engineers. He established his own firm, Foster & Vassar, in New York in 1922 and he served as consulting architect to the Office of the Supervising Architect from 1934 to 1942. In partnership with Gilbert Stanley Underwood, he was the consulting design architect to the Office of the Supervising Architect for the War Department building, completed in 1940, as well as the West Heating Plant in Georgetown, completed in 1948. He formed the architectural firm of Howe, Foster & Snyder in 1947. In his later career he completed numerous residential projects in the Colonial Revival style and worked extensively in Georgetown; Foster participated in the restoration of Octagon House and was a founder of the Committee to Preserve the Capitol.