Complex sentence: After college, Sullivan had a short professional football career playing first with the Atlanta Falcons from 1972 to 1976 and then the Washington Redskins in 1976 and 1977.
Split into simpler sentences: After college, Sullivan had a short professional football career. He played with the Falcons from 1972 to 1976 and then the Washington Redskins in 1976 and 1977.