During the Massive Resistance crisis, the Democratic Byrd Organization proposed the closure of Virginia's public schools in an effort to prevent racial desegregation required by the United States Supreme Court decision in Brown v. Board of Education.
Giesen's mother was editor of the Women's page in the local newspaper, ran against the incumbent Byrd Democrat, and won election to the Virginia House of Delegates in 1958.
Two years later, in 1963, he came in second, since Democrat Felix E. Edmunds, who had come in second the previous election (and had only lost in 1955 because the district had briefly become a single-candidate one), had decided to concentrate on his legal practice.
On September 11, 1974, he resigned his House seat and leadership position, hoping to win the special election to succeed H. Dunlop Dawbarn in the state senate.
[10] From 2007 until his death, Giesen taught courses on state and local government at James Madison University in Harrisonburg, about 20 miles north of his Augusta County home.