This oral history interview with John D. Mosser was conducted by Clark Hansen at Mosser’s home in Portland, Oregon, from November 15 to December 11, 1990. In this interview, Mosser discusses his family background and early life in the suburbs of Chicago, Illinois. He talks about attending Princeton and working on the school newspaper, as well as his service in the U.S. Army during World War II, which interrupted his education. He details his experience fighting on the front lines in France. He discusses studying law at Yale, his marriage to Priscilla Alexander, and coming to Oregon to practice law, primarily admiralty law, in 1950.

Mosser discusses his involvement with the Republican Party and his legislative service in the Oregon House of Representatives in 1957, including his campaign. He discusses legislation he worked on, particularly on education. He then discusses his activities before he re-entered the Legislature in 1963, including lobbying and raising a family. He goes on to talk about his return to the Oregon House of Representatives from 1963 to 1966. He discusses additional education legislation that he worked on, as well as legislation on taxes, labor, and land use. He speaks at length about the many legislators he worked with, particularly Vera Katz and Vic Atiyeh. He discusses his reasons for leaving the Legislature and his subsequent activities, including serving on the Board of Education and the Land Conservation and Development Commission, continuing his law practice, and leaving the Republican Party. He discusses serving on the Portland Waterfront Commission in the late 1960s, and his involvement in the creation of Tom McCall Waterfront Park. He closes the interview by talking about his family.