Bill Russell passed away at the age of 88, leaving behind one of the best legacies from any athlete in history. Former President Barack Obama was one of the many voices to pay their respects to Russell, the legendary Boston Celtics center.

In a three-tweet thread, Obama said that losing Russell means losing “a giant” whose legacy features much more than his work on the basketball court.

Barack Obama honored Bill Russell with the Presidential Medal of Freedom in 2011. At the ceremony, the first Black president of the United States highlighted that Russell was the first Black head coach in the major American sports leagues. Russell took the reins from his former coach, Red Auerbach, to become the Celtics' player-coach and led them to two championships.

Obama highlighted in the speech how Russell participated in the March on Washington with Martin Luther King Jr. and stood up for Muhammad Ali. Russell's amazing work with civil rights made him just as legendary as his basketball career did. In his Twitter thread, he mentioned the horrible, racist acts Russell endured throughout his career with the Celtics and how it never made him stop his civil-rights work.

“Perhaps more than anyone else, Bill knew what it took to win and what it took to lead,” Obama continued in his Twitter thread. “On the court, he was the greatest champion in basketball history. Off of it, he was a civil rights trailblazer—marching with Dr. King and standing with Muhammad Ali.”

Bill Russell advocated for civil rights well into the later years of his life and cherished the medal he received from Obama. He tweeted a picture of himself taking a knee to protest injustice while wearing it in 2017, roughly a year after Colin Kaepernick's peaceful protests.

Bill Russell won 11 championships in his 13-year career with the Celtics. He was named to the Basketball Hall of Fame in 1975 and racked up five MVPs and 12 All-Star Games.