Weigl enlisted in the United States Army shortly after his 18th birthday and spent three years in the service. He served in the Vietnam War from December 1967 to December 1968 and received the Bronze Star. When he returned to the United States, Weigl obtained a bachelor's degree from Oberlin College, and a Master of Arts Degree in Writing/American and British Literature from the University of New Hampshire. From 1975-76, Weigl was an instructor at Lorain County Community College in Elyria, Ohio.