McCartney's 1990 team was crowned as national champions by the Associated Press, splitting the title with Georgia Tech, who was first in the final Coaches' Poll.
After receiving his Bachelor of Arts in education from the University of Missouri in 1962, where he was a member of the Pi Kappa Alpha fraternity,[1] McCartney was named as an assistant football coach under his older brother, Tom, in the summer of 1965 at Holy Redeemer High School in Detroit, Michigan.
[2] The younger McCartney was also the head basketball coach at Redeemer from 1965 to 1969, taking the school to the Detroit City Championship during the 1968–69 season.
[6] After eight years as an assistant at Michigan, McCartney was hired to replace Chuck Fairbanks as head coach at the University of Colorado Boulder on June 9, 1982.
[13] At that point, McCartney agreed to back away from religious expressions in his role as coach, but increasingly engaged in advocacy for socially conservative policy in his personal life.
[15] Nonetheless, Colorado won all eleven of its regular season games including victories over ranked Washington, Illinois, Nebraska, and Oklahoma.
Colorado opened the 1990 season ranked fourth with a game against Tennessee in the inaugural Disney Pigskin Classic in Anaheim, California, which ended in a 31–31 tie.
In a game against Missouri on October 6, the officials mistakenly allowed an extra down on which Colorado scored the winning touchdown as time expired.
The Buffaloes won a closely played game 10–9, aided by a questionable and debated clipping call that negated a late punt return touchdown by Rocket Ismail of Notre Dame,[16][17][18] and earned a share of the national title.
Colorado won the game 27–26 on a 64-yard Hail Mary pass from Kordell Stewart to Michael Westbrook as time expired, which has since become known as The Miracle at Michigan.
[21] In 1995, there was widespread media speculation that McCartney might un-retire to serve as the head coach at Michigan following the resignation of Gary Moeller.
[22][23] McCartney, a former Wolverines assistant coach under Bo Schembechler, held a news conference to remove his name from consideration, stating that he wanted to devote his time to Promise Keepers.
McCartney was on the forefront to support the 1992 Amendment 2 to the Colorado Constitution, which prevented the passage of anti-discrimination laws giving protected status to gays, lesbians, or bisexuals.