Criticism continues to mount against NFL teams for failing to offer a contract to Colin Kaepernick after the quarterback took a stand—or, rather, a knee—during performances of the National Anthem last season in protest of  police brutality, racism, and unfair treatment toward Black Americans.

FILE – In this Nov. 20, 2016, file photo, San Francisco 49ers quarterback Colin Kaepernick (7) kneels next to outside linebacker Eli Harold (58) and safety Eric Reid, right rear, during the national anthem before an NFL football game against the New England Patriots in Santa Clara, Calif. It’s been a week since Baltimore Ravens coach John Harbaugh floated the idea of adding Kaepernick, a veteran who has Super Bowl experience and the baggage that comes from his decision last year to literally sit out the National Anthem on game day. (AP Photo/Marcio Jose Sanchez, File)

While Kaepernick’s efforts have everyone talking, he is not the first athlete to use a platform to make his voice heard. Here are a list of athletes past and present who have also made a statement.

Muhammad Ali

The late boxer was never one to be silent on the issues of oppression. Ali made history on April 28, 1967 when he refused to be drafted in the Vietnam War saying, “I ain’t got no quarrel with those Vietcong.” Ali, a Muslim, cited religious beliefs as his reason for resisting the draft. Due to Ali’s refusal to participate in the war, he was stripped of his heavyweight title, sentenced to five years in prison, fined $10,000, and banned from boxing for three years. Ali returned to the ring in October 1970 in a match between him and Jerry Quarry. On June 28, 1971 the United States Supreme Court overturned his conviction.

Tommie Smith and John Carlos

Known as one of the most overtly political statements of the modern Olympic games, the famous Black Power salute at the 1968 Summer Olympics in Mexico City was conducted by Tommie Smith and John Carlos. Having won gold and bronze respectively in the 200 m race, during the medal ceremony the two athletes raised their black-gloved fists and looked downward toward the podium as the National Anthem played. Smith and Carlos wore badges for the Olympic Project for Human Rights on their jackets, and the silver medalist, white Australian sprinter Peter Norman joined them in wearing the badge. After the men left the podium, a boo erupted from the crowd.

Smith later said, “If I win, I am American, not a Black American. But I did something bad, then they would say I am a Negro. We are Black and we are proud of being Black. Black America will understand what we did tonight.”

The International Olympic Committee president Avery Brundage deemed their protest unfit for the apolitical, international forum of the Olympic Games. He ordered Smith and Carlos to be suspended from the U.S. track team and banned from the Olympic Village. When the U.S. Committee refused, Brundage threatened to suspend the entire U.S. track team. This threat led to the expulsion of the two athletes.

In later years, Smith addressed the political statement once again saying, “We were concerned about the lack of Black assistant coaches. About how Muhammad Ali got stripped of his title. About the lack of access to good housing and our kids not being able to attend the top colleges.”

Mahmoud Rauf-Abdul

The former Denver Nuggets player decided to make a statement during the 1995-96 NBA season, opting to no longer stand and salute the American flag during the National Anthem. During the singing of the “Star-Spangled Banner” Abdul-Rauf would stand with his hands on his hips, or more commonly stretch, for the entire duration of the song.

After a local reporter noted this protest, NBA Commissioner David Stern handed Abdul-Rauf a one-day suspension for his refusal to stand. Two days later, the NBA and Abdul-Rauf reached a compromise, allowing Abdul-Rauf to stand and close his eyes or look downward to the floor during the singing of the National Anthem. The point guard would say a Muslim prayer during the performance.

Despite the NBA reaching a compromise with the player, racist America had already grown to dislike Abdul-Rauf. That acrimony caused him to be traded to the Sacramento Kings, where he was ultimately benched during the two seasons he was with the team. After his contract with the Kings expired, he was unable to obtain a contract with any other NBA team, and left the U.S. to play basketball in Europe and Japan. He ultimately retired at the peak of his career in 1999.

Even after enduring death threats and having his home burned to the ground, Abdul-Rauf said in a September 2016 interview, “It’s priceless to know that I can go to sleep knowing that I stood to my principles. Whether I go broke, whether they take my life, whatever it is, I stood on principles. To me, that is worth more than wealth and fame.”

Ariyana Smith

When Knox College’s Division III women’s basketball team played an away game against Fontbonne University in Clayton, Mo. on November 29, 2014, Knox player Ariyana Smith decided that she would be the first athlete to publicly speak out against police brutality.

Smith staged a nearly five-minute protest before the game, making a “hands up, don’t shoot” gesture during the National Anthem before approaching the American flag and lying under it for four and a half minutes, symbolism for the four and a half minutes Ferguson police allowed Michael Brown’s body to lie in the street before removing him. When she stood, she raised the Black power salute before walking out of the gym with her fists still raised.

Days later, Knox College Athletic Director Chad Eisele indefinitely suspended Smith from athlete participation for breaking protocol on athletes leaving the game. That suspension was cut to one game, and then reversed entirely a day later, a decision Smith said she believed was only the result of media attention to her actions.

Marshawn Lynch

Oakland Raiders running back Marshawn Lynch was the most recent athlete to protest during the National Anthem. In the Raiders preseason opener against the Arizona Cardinals on Aug. 12, Lynch chose to sit on a cooler during the National Anthem and eat a banana. Lynch has stated that he has not stood for the anthem for 11 years (although there are instances in which Lynch has been seen standing).

Neither the team nor the league took action against Lynch; Raiders’ owner Mark Davis had Tommie Smith light the ceremonial Al Davis Torch during the team’s game in Mexico City last November. Davis also stated last year that he prefers if players protest out of uniform, there would be no punishment if they participated in such acts.

While political statements by athletes go back decades, Sha’Dawn D. Battle, assistant professor of English at Wittenberg University told the AFRO that athletes of the past were more politically visible.

“Muhammed Ali and other athletes were more politically visible because they had an active, visible, and definable political movement underway in their historical eras,” Battle said. “In this Post-9-11/Obama era, youth, athletes, music artists, etc., don’t recognize that the BLM is the postmodern Black Liberation movement, and they don’t see hyper visible, virile leaders with whom they can look to for guidance and with whom they can forge an alliance.”

“Also, if it’s not police brutality, many of them can’t recognize, let alone articulate the state of injustice in which we exist,” she added. “So it was easier back in the day because their whole existence was politicized almost inevitably. Also, there’s the fact that today…these athletes are receiving ridiculous max contracts and they’re not trying to jeopardize that.”