When he was 17 years old, Molesworth stood 5 feet 7 inches (1.70 m) tall and weighed 98 pounds (44 kg).
Molesworth started his pro football career at the semipro Rock Island Independents in 1927 for $25-a-game.
[2] He later played for the independent professional Ironton Tanks, who helped defeat the Chicago Bears in November 1930 and impressing George Halas in the process.
After the Ironton Tanks folded in 1931, he tried out for the Bears and went on to play seven seasons with the team, where he was the T-formation quarterback in a backfield that included Red Grange and Bronko Nagurski.
He remained with the club as a vice president and director of personnel until dying of a heart attack on March 12, 1966, while seeding his lawn, at the age of 60.