Which college was Gale Sayers playing for when he entered the NFL?

Which college was Earl Campbell playing for when he entered the NFL? What jersey number did Earl Campbell wear with the Oilers? What position did Gale Sayers primarily play? Gale Sayers is best known for playing with which NFL team? What jersey number did Gale Sayers wear with the Bears? What position did Marcus Allen primarily play? Marcus Allen is best known for playing with which NFL team? Which college was Marcus Allen playing for when he entered the NFL?