Letlow played his college career at the University of San Francisco. Prior to the 1936 NFL draft, college players were free agents that could sign with an NFL team; Letlow had signed with the Chicago Cardinals prior to the draft. Subsequently, he was chosen by the Green Bay Packers as their first-round draft pick in the inaugural 1936 NFL draft.[2] After being drafted by Green Bay, he was released by the Cardinals.[3]
In Letlow's rookie season, the Packers won their fourth NFL Championship (and first championship game). Letlow played for the Packers from 1936 to 42, and again in 1946. He was selected as an All-Pro for four straight seasons from 1937 to 1940. He played in 71 career games while starting in 30 of them. He was named to the All-Star game, the predecessor to the Pro Bowl in 1938 and 1939. He went into the Navy in 1943, being named to the All-Service team in 1943 and 1944. He returned to the Packers for one more season in 1946.
