Emlen was an outstanding all-around athlete at Radnor High School. In football, he was an All-League, All-Delco, and All-Scholastic performer before matriculating to the University of Toledo. Unfortunately, he broke his neck in his season, but recuperated to lead Toledo's basketball team to an N.I.T. berth. After a stint in the Coast Guard, Emlen resumed his football career at the University of Iowa. In the N.F.L., he played with the New York Giants (1948-58), and Green Bay Packers(1959-61), where he was named All-Pro four times and played in eight Pro Bowls. Emlen played in 165 N.F.L. games, 158 consecutively, both were records at one time. At one time, he held N.F.L. records for interceptions (79), and punt returns (758). Rated as the all-time best safety, he became the first black player elected to the Pro Football Hall of Fame.