College Thornton played fullback and linebacker at
Nebraska from 1960 to 1962. After his junior season in 1961, the
Associated Press named Thornton a
first-team Big Eight fullback, as well as an honorable-mention All-American. A pre-season separated shoulder injury shortened Thornton's 1962 senior season. He still served as a co-captain and became an honorable mention All-Big Eight selection. After the season, Thronton played in the
East–West Shrine Bowl in
San Francisco. During his senior year Thornton was the first black athlete inducted into the
Innocents Society, the
University of Nebraska's chancellor's club that honors outstanding seniors for their academic and leadership abilities.
NFL Thornton was drafted by the
St. Louis Cardinals with the 58th pick (5th round) in the
1963 NFL draft. He played for the Cardinals from 1963 to 1965 and in 1967, appearing in 47 games. ==Coaching career==