Playing for Southern University, Blount made the Southwestern Athletic Conference (SWAC) all-conference team twice and was selected SWAC Most Valuable Player (MVP) his junior year. He was selected by the Pittsburgh Steelers in 1970 as the fifty-third overall pick. He led the NFL in interceptions in 1975 with eleven and was named NFL Defensive MVP for that year. He helped the Steelers win four Super Bowls and played in five Pro Bowls, earning MVP honors in the 1976 game. He played in 200 games and missed only one over the course of 14 seasons.
