Simplify the following text for a Grade 9 native English-speaking person.
Original: Leon H. `` Bud '' Carson ( â `` ) was an American football coach best-known for working with the Pittsburgh Steelers ' championship teams of the 1970s .
Simplified: Leon H. `` Bud '' Carson ( â `` ) was an American football coach best-known for his role on the Pittsburgh Steelers ' championship teams of the 1970s .