American football coach from the United States
According to Wikipedia,
William E. Callahan is an American football coach who is the offensive line coach for the Cleveland Browns of the National Football League . He was formerly the head coach of the Oakland Raiders for the 2002 and 2003 seasons and led them to Super Bowl XXXVII. He was also the head coach for the Nebraska Cornhuskers from 2004 to 2007 and the offensive line coach and interim head coach for the Washington Redskins from 2015 to 2019.
Bill Callahan is affiliated with the following schools: