Born in Sheboygan, Wisconsin, Marotz graduated from Shawano High School. During World War II, Marotz served in the United States Marine Corps in the Pacific Theater from August 1941 to November 1943. He was sent to Officer Candidate School at Bowling Green State University and Dartmouth College. He was a member of the Wisconsin State Assembly from 1949 through 1959. He served five terms from Shawano County, Wisconsin in the Legislature, as Majority Leader from 1955 to 1957, and was elected Speaker of the Assembly from 1957 to 1959.
