In 1972, redistricting put Wilhelm in the same district as Representative Fred Hadley. With neither of them wanting to move or retire, they went on to face each other in the primary election for the Republican nomination. In the end, Hadley defeated Wilhelm, successfully ending his time in the legislature.
He died in 1991.
A former employee of both Kroger and the United Telephone Company, Wilhelm initially ran to represent Van Wert County in the Ohio House of Representatives in 1964, and won a seat. When the Voting Rights Acting of 1965 initiated legislative districts in 1966, Wilhelm won reelected to represent the newly drawn Second District. He ran unopposed for a third term in 1968, and won a fourth term in 1970.
Following his defeat, Wilhelm served in the private sector, and publicly as a member of the Ohio state lottery commission.
