William E. Callahan (born July 31, 1956) is an American football coach who is the offensive line coach for the Cleveland Browns of the National Football League (NFL). He was 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. Callahan is considered to be one of the best offensive line coaches in the NFL. College career Callahan was a four-year starter at quarterback at Illinois Benedictine College in Lisle, Illinois, where he was an NAIA honorable mention All-American in his final two seasons. Early coaching career The Chicago native began his coaching career in 1978 with back-to-back year-long stints as an assistant coach at Oak Lawn Community High School and De La Salle Institute. Callahan started his college coaching career shortly after in 1980 as a graduate assistant at the University of Illinois before being promoted to full-time assistant in 1981, coaching tight ends, offensive line, quarterbacks and special teams through 1986. Callahan served a two-year stint from 1987–1988, as offensive line coach at Northern Arizona University and one year as offensive coordinator of Southern Illinois in 1989. From 1990–1994, Callahan was offensive line coach at the University of Wisconsin–Madison. He has been praised by former Wisconsin coach Barry Alvarez as being one of the primary reasons why the Badgers were able to turn their program around and eventually win three Rose Bowls in the 1990s. Alvarez cited Callahan specifically for his strong recruiting abilities. At Southern Illinois in 1989, Callahan led an offense that ran for 1,245 yards and threw for 2,569 yards with 19 touchdowns. As of 2011, the 238 completions and 432 pass attempts were second most in school history in both categories. At Wisconsin after a 1–10 season in 1990, Callahan helped pave the way for Terrell Fletcher to run for 446 yards in 1991. In 1992, that number jumped to 492 and Brent Moss ran for 739 yards and 9 touchdowns. By 1993, Wisconsin's offensive line paved the way for Moss' 1,637 yards and 16 touchdowns. Fletcher also ran for 996 yards and 9 touchdowns. Quarterback Darrell Bevell was able to throw for 19 touchdowns. In 1994, Bevell would throw 17 touchdowns and