On July 24, 1948, Tunnell signed with the New York Giants. He was the first African American signed by, and the first to play for, the Giants. He later wrote that he hitchhiked from his family home in Garrett Hill to New York City to meet Jack Mara, son of Giants founder Tim Mara, and ask for a try out. In his Hall of Fame induction speech, Tunnell thanked a West Indian banana-truck driver who dropped him off near this Polo Grounds "appointment".