Major Williamson was a veteran of World War II. In Korea, he was a member of Headquarters and Headquarters Company, I Corps. He developed acute pancreatitis and was taken to the 121st Evacuation Hospital where he died on 14 February 1952.

Williamson was awarded the Purple Heart, the Combat Infantryman Badge, the Korean Service Medal, the United Nations Service Medal, the National Defense Service Medal, the Korean Presidential Unit Citation, the Republic of Korea War Service Medal and the World War II Victory Medal.