The cause of death had yet to be determined.
Cunningham, who was inducted into the College Football Hall of Fame in 1992, is widely recognized for helping speed up the process of integration in football programs across the South. Cunningham ran for 135 yards and two touchdowns as USC beat an all-white Alabama team to open the 1970 season. That performance, coupled with those of his Black teammates, was pivotal in Alabama coach Bear Bryant's decision to recruit Black players.
"What they saw was the future,'' Cunningham told ESPN in 2016. "Their team was eventually going to be integrated.''
In 1971, Alabama had Black players on scholarship for the first time and played for the national title. However, the Crimson Tide were routed 38-6 by Nebraska in the Orange Bowl. But the decade became a standout era for Bryant and the Crimson Tide as they went on to win three national championships.
Jerry Claiborne, a former Bryant assistant, famously said, "Sam Cunningham did more to integrate Alabama in 60 minutes than Martin Luther King did in 20 years.''
Lynn Swann, a teammate of Cunningham's at USC, said, "The entire SEC, especially Alabama, owes Sam Cunningham a tremendous debt of thanks and appreciation for his play that opened the door to Black athletes in 1970.
"There are a lot of athletes who have done their share and more to end discrimination in so many ways. But Sam opened a huge door in the South and in that conference, which did more for minorities and young Black men to have the opportunity to play in the SEC and get an education."
Cunningham earned All-American honors in 1972, when he captained the Trojans to a national championship. One of his best college performances came against Ohio State in the 1973 Rose Bowl, when he ran for four touchdowns, earning MVP honors, in a 42-17 win.
He ran for 1,579 yards and 23 touchdowns in his USC career, including 13 TDs in 1972. The Trojans had a record of 24-8-2 during his three years when Cunningham earned the nickname "Bam'' for his bruising goal-line dives.
"It became a bit of a legend with Sam going over the top of an offensive line,'' Swann said. "Nobody could stop him.''
Cunningham was selected No. 11 overall in the 1973 NFL draft by the Patriots and went on to play nine seasons for the team, becoming the franchise's all-time leading rusher.
He was a Pro Bowl selection in 1978, when the Patriots set an NFL record for rushing yards as a team with 3,165. The mark stood until 2019, when it was broken by the Baltimore Ravens.
Cunningham finished his NFL career with 5,453 yards rushing and 49 touchdowns before retiring after the 1982 season.
He was later inducted into the Rose Bowl Hall of Fame (1992), USC Athletics Hall of Fame (2001) and Patriots Half of Fame (2010).
"Sam 'Bam' Cunningham was one of my favorite players throughout the '70s and my sons all loved him," Patriots owner Robert Kraft said in a statement. "After I bought the team in 1994, it was my honor to welcome him back to the team on multiple occasions, recognizing him as a 50th anniversary team member and again for his induction into the Patriots Hall of Fame.
"As much as I admired him as a player, my affection for him only grew after spending time with him and learning more about him as a person. He made a tremendous impact, both on and off the field, and was beloved by his teammates. As a Patriots Hall of Famer, Sam's legacy and contributions will be preserved and celebrated forever, but today his loss is felt with heavy hearts."
After his playing career, Cunningham worked as a landscape contractor in California. He was born and raised in Santa Barbara.
Cunningham is survived by his wife, Cine, daughter Samahndi, brothers Bruce, Anthony and Randall, who starred as a quarterback in the NFL for 16 years, niece Vashti Cunningham, a world champion high jumper and nephew Randall II.
The Associated Press contributed to this report.