Question: The 1955 Northwestern Wildcats football team were led by which future Denver Broncos head coach?

Context paragraphs:
1996 Northwestern Wildcats football team: The 1996 Northwestern Wildcats football team represented Northwestern University in the 1996 NCAA Division I-A college football season.  Under head coach Gary Barnett, Northwestern finished the season with a 9–3 record.  The Wildcats won a share of the Big Ten Conference title for the second straight year.  They faced off against Tennessee in the Florida Citrus Bowl, where the Wildcats lost, 48–28.

2014 Northwestern Wildcats football team: The 2014 Northwestern Wildcats football team represented Northwestern University during the 2014 NCAA Division I FBS football season.  Pat Fitzgerald, who was in his ninth season at Northwestern, as the team's head coach.  The Wildcats home games were played at Ryan Field in Evanston, Illinois.  They were members of the new West Division of the Big Ten Conference.  They finished the season 5–7, 3–5 in Big Ten play to finish in a tie for fifth place in the West Division.

2006 Northwestern Wildcats football team: The 2006 Northwestern Wildcats football team represented Northwestern University in the Big Ten Conference during the 2006 NCAA Division I FBS football season.  Head coach Randy Walker died unexpectedly on June 29, 2006 of an apparent heart attack at the age of 52.  Pat Fitzgerald, seen by many before the tragedy as Walker's eventual successor, was promoted from linebackers coach and recruiting coordinator to head coach on July 7.  The Wildcats also had to replace their offensive coordinator, offensive line coach, and Brett Basanez, the team's former four-year starter at quarterback and holder of dozens of school records.  Not surprisingly, the 2006 season was not as successful as previous years.

Horace Butterworth: Horace C. Butterworth (December 3, 1868 – December 8, 1939) was the first head coach for the Chicago Maroons men's basketball team, the fourth head football coach for the Northwestern Wildcats baseball team as well as the fourth head coach for the Temple Owls football team.  Additionally, Butterworth was the fourth athletic director for Northwestern and maintain the position from 1903 to 1904.  Butterworth attended Delaware College for his undergraduate studies and completed his doctorate from the University of Chicago in 1898.  Even though he had a record of 10–4, his time as the Chicago Maroons head coach was cut short when the university suspended the program based on a lack of interest.  In his only season as the Northwestern Wildcats baseball coach his team played a 17-game season, of which 12 games were verses Western Conference opponents.  At Temple, his coaching record was 4–0–2.  This ranks him 16th at Temple in total wins and first at Temple by winning percentage.

1955 Northwestern Wildcats football team: The 1955 Northwestern Wildcats team represented Northwestern University during the 1955 Big Ten Conference football season.  In their first year under head coach Lou Saban, the Wildcats compiled a 0-8-1 record (0-6-1 against Big Ten Conference opponents), finished in last place in the Big Ten, and were outscored by their opponents by a combined total of 241 to 66.

2012 Northwestern Wildcats football team: The 2012 Northwestern Wildcats football team represented Northwestern University during the 2012 NCAA Division I FBS football season.  Pat Fitzgerald, in his seventh season at Northwestern, was the team's head coach.  The Wildcats home games were played at Ryan Field in Evanston, Illinois.  They were members of the Legends Division of the Big Ten Conference.  The Wildcats won their first bowl game since the 1949 Rose Bowl against California by defeating Mississippi State in the Gator Bowl 34–20.  They finished the season 10–3 (5–3 Big Ten).

Lou Saban: Louis Henry Saban (October 13, 1921 – March 29, 2009) was an American football player and coach.  He played for Indiana University in college and as a professional for the Cleveland Browns of the All-America Football Conference between 1946 and 1949.  Saban then began a long coaching career.  After numerous jobs at the college level, he became the first coach of the Boston Patriots in the American Football League (AFL) in 1960.  He joined the Buffalo Bills two years later, and led the team to consecutive AFL championships in 1964 and 1965.  After serving briefly as head coach at the University of Maryland, he was hired as head coach of the Denver Broncos in 1967, where he remained for five years.  Saban returned to the Bills—by then in the National Football League following the AFL–NFL merger—from 1972 to 1976, reaching the playoffs once but failing to bring Buffalo another championship.

2009 Northwestern Wildcats football team: The 2009 Northwestern Wildcats football team represented Northwestern University in the Big Ten during the 2009 NCAA Division I FBS football season.  Pat Fitzgerald, in his fourth season at Northwestern, was the team's head coach.  The Wildcats home games were played at Ryan Field in Evanston, Illinois.  The Wildcats finished the season 8–5, 5–3 in Big Ten play and lost in the Outback Bowl 35–38 in overtime against Auburn.

2013 Northwestern Wildcats football team: The 2013 Northwestern Wildcats football team represented Northwestern University during the 2013 NCAA Division I FBS football season.  Pat Fitzgerald, in his eighth season at Northwestern, was the team's head coach.  The Wildcats home games were played at Ryan Field in Evanston, Illinois.  They were members of the Legends Division of the Big Ten Conference.

2016 Northwestern Wildcats football team: The 2016 Northwestern Wildcats football team represented Northwestern University during the 2016 NCAA Division I FBS football season.  They awere led by Pat Fitzgerald who is in his 11th season as the team's head coach.  The Wildcats home games were played at Ryan Field in Evanston, Illinois.  They were members of the West Division of the Big Ten Conference.

Supporting paragraphs: 1955 Northwestern Wildcats football team Lou Saban
Answer: Louis Henry Saban