Graesslin graduated Janesville High School class of 1943. At the June commencement exercises he was awarded two scholarships - Hi-Y and Milton. He was an outstanding member of the all Janesville High School sport aggregations known for his aggressive leadership. In his last season of football in 1942, although carrying a knee injury during the last part of the season, he figured in the most important games and was a constant threat to his opponents because of his accurate passes - and his leadership. With "Fritz" as the spark plug the 42 Football team tied with Kenosha for the Big Eight championship. While listed as a reserve on the Bluebird basketball team, Graesslin was elected captain for the all-important Beloit game, which was won by Janesville to keep a clean record of continuous wins against Beloit during his sports career at Janesville High School.

Fred lived just down the block from the Robert Kasmarek, father of James Kasmarek, who has provided the newspaper articles and regarding F/O Graesslin and MACR # 14511 for the Kobler Crew). Fritz and Robert spent a lot of time together; they were the best of friends. In the team pictures from football and basketball, Fritz and Robert are almost always side-by-side.

Entering into the service Army Air Corps 23 July 1943. Graesslin took training at three Texas camps, two in Nebraska, at Clovis, New Mexico, radar work in Victorville California, University of Toledo, Toledo Ohio and Miami Beach, Florida. He received the silver wings of Flight Officer in November 1944 at Hondo Field, Texas. Leaving California May 4, 1945, he crossed the International Date Line May 7, on his 20th birthday.

Bob Hanewall, a close friend, had made plans to meet Graesslin on 27 May. When he went to the North Field for their dinner date he found that Fred and his crew hadn't returned according to the Officer in charge of Graesslin's Quonset hut. Hanwell and Graesslin were both from Janesville and after each entering in the service they met in Hawaii and again on Guam.

Fritz had a sister named Phyllis and a younger brother named Bob.