Question: Which American football running back won a Heisman Trophy in the 70"s?
Context: Earl Christian Campbell (born March 29, 1955) is a former American football running back who played professionally in the National Football League (NFL) for the Houston Oilers and New Orleans Saints.  Known for his aggressive, punishing running style and ability to break tackles, Campbell gained recognition as one of the best power running backs in NFL history. The 1977 Texas Longhorns football team represented the University of Texas at Austin in the 1977 NCAA Division I football season.  The Longhorns finished the regular season with an 11–0 record.  Earl Campbell won the Heisman Trophy in 1977 and led the nation in rushing with 1,744 yards.  In 1977, he became the first recipient of the Davey O'Brien Memorial Trophy, which was awarded to the most outstanding player in the now-defunct Southwest Conference.  He was selected as the Southwest Conference running back of the year in each of his college seasons and finished with 4,444 career rushing yards. Andre Rishard Williams (born August 28, 1992) is an American football running back for the Los Angeles Chargers of the National Football League (NFL).  He was drafted by the New York Giants in the fourth round of the 2014 NFL Draft.  He played college football at Boston College, where he was a finalist for the 2013 Heisman Trophy, and won the 2013 Doak Walker Award as the nation's best running back.  During the 2013 season, Williams became only the 16th player in NCAA history to rush for over 2,000 yards and he finished his college career ranked 5th all-time for most yards rushed in a single season with 2,177 yards. William Abb Cannon (born August 2, 1937) is a former American football running back and tight end who played professionally in the American Football League (AFL) and National Football League (NFL).  He attended Louisiana State University (LSU), where he played college football as a halfback and return specialist for the LSU Tigers.  At LSU, Cannon was twice unanimously named an All-American, helped the 1958 LSU team win a national championship, and received the Heisman Trophy as the nation's most outstanding college player in 1959.  His punt return against Ole Miss on Halloween night in 1959 is considered by fans and sportswriters to be one of the most famous plays in LSU sports history. Adrian Lewis Peterson (born March 21, 1985) is an American football running back for the New Orleans Saints of the National Football League (NFL).  He played college football at Oklahoma and was drafted by the Minnesota Vikings seventh overall in the 2007 NFL Draft.  Peterson set the NCAA freshman rushing record with 1,925 yards as a true freshman during the 2004 season.  As a unanimous first-team All-American, he became the first freshman to finish as the runner-up in the Heisman Trophy balloting.  Peterson finished his college football career as the Sooners' third all-time leading rusher. Ivan Charles "Tucker" Frederickson (born January 12, 1943) is a former American football running back for the New York Giants of the NFL.  Frederickson attended South Broward High School then moved on to Auburn University, and was a two-way player with the Tigers football team (averaging 4.4 yards per carry on offense and leading the team in interceptions as a safety on defense).  In 1964, he won the Jacobs Award as the best blocking back in the Southeastern Conference and was a runner up in the Heisman Trophy race.  Coach Shug Jordan called him "the most complete football player I've ever seen".  He was an All-American in 1964.  Frederickson was the first overall pick in the 1965 NFL Draft having been selected by the New York Giants, with whom he played until a knee injury forced his retirement in 1971 (six total playing seasons).  Frederickson was inducted in the College Football Hall of Fame in 1994. Errick Lynne "Ricky" Williams Jr. (born May 21, 1977) is a retired American football running back who played twelve seasons in the National Football League (NFL) and one season in the Canadian Football League (CFL).  He played college football for the University of Texas, where he was a two-time All-American and won the Heisman Trophy.  Williams was drafted by the New Orleans Saints fifth overall in the 1999 NFL Draft and spent three seasons with the team before he was traded to the Miami Dolphins in 2002.  He played for the Dolphins for two seasons, and retired for the first time from football in 2004.  Due to his suspension from the NFL in 2006, he played for the Toronto Argonauts that year.  Williams re-joined the Dolphins in 2007 and played with them until 2010, and spent the 2011 season with the Baltimore Ravens.  He was formerly an assistant football coach at the University of the Incarnate Word and is currently a football analyst for ESPN's Longhorn Network.  In 2015, Williams was inducted into the College Football Hall of Fame. The Heisman curse is a term coined to reference a two-part assertion of a negative future for the winning player of the Heisman Trophy.  The "curse" supposes that any college football player who wins the Heisman plays on a team that will likely lose its subsequent bowl game.  The trend of post-award failure has garnered the attention of the mainstream media.  Talk of a curse in relation to bowl results was particularly prevalent from 2003 to 2008, when six Heisman Trophy winners compiled a cumulative 1–5 bowl game record, and five of those six led number one ranked teams into the Bowl Championship Series (BCS) National Championship Game as favorites (Heisman Trophy winners, including Reggie Bush, who gave back his Heisman Trophy, are 4–8 overall in the BCS National Championship Game and College Football Playoff National Championship, although prior to 2009 they were 1–6).  Additionally, the Heisman curse asserts that in most cases a Heisman winner will have either a poor career in the National Football League (NFL), or in fact not even see such a football career at all.  Although many Heisman winners have not enjoyed success at the professional level, including players like Matt Leinart, Andre Ware, Jason White, Rashaan Salaam, Eric Crouch, Ty Detmer, Troy Smith and Gino Torretta, proponents of the "curse" rarely cite highly successful players such as Barry Sanders, Charles Woodson, Eddie George, Tim Brown, Bo Jackson, Marcus Allen, Earl Campbell, and Tony Dorsett among the notables. Tobin Bo Gunnar Gerhart (born March 28, 1987) is an American football running back who is currently a free agent.  He was selected by the Minnesota Vikings in the second round of the 2010 NFL Draft.  He played college football for Stanford University, and was a unanimous All-American.  In 2009 Gerhart won the Doak Walker Award and was the runner-up for the 2009 Heisman Trophy.  He received 1,276 points in the Heisman voting, coming in second to Mark Ingram Jr., who received 1,304 points; the 28-point margin was the closest vote in Heisman history.  Gerhart had a breakout senior season in 2009, leading all running backs in the nation in rushing yards, touchdowns, and points scored, and setting several Pac-10 and school records.  He held the Stanford record for most rushing yards in a season (1,871) until Christian McCaffrey broke it in 2015, but still holds Cardinal records for touchdowns in a season (28), and most touchdowns in a career (44). Edgar Francis "Special Delivery" Jones (May 6, 1920 – May 15, 2004) was an American football running back who played for the Chicago Bears of the National Football League (NFL) and the Cleveland Browns of the All-America Football Conference (AAFC).  Jones played college football at the University of Pittsburgh where he finished seventh in the Heisman Trophy voting in 1941.
Answer: Earl Campbell