Like other celebrities, Black athletes have the command of an audience. Throughout history, athletes – from Olympic track stars and professional boxers to pro football players have taken a stand on social justice issues.

The most recent history of athlete protest would be that of National Football League quarterback Colin Kaepernick, whose quiet kneeling protests during the singing of the national anthem essentially ended his professional football career. Kaepernick knelt to protest police violence against Black people. The first time he did so was as a San Francisco 49er on Sept. 1, 2016, in San Diego, with teammate Eric Reid. Prior to this he would sit during the anthem. He played his final game with the 49ers on Jan. 1, 2017.

Civil rights activist Dr. Martin Luther King once said, “I wish that I had a lot more time for sports. You people in sports have done a great job giving the Negro equal rights, and you have achieved that without bloodshed.”

Here are nine times politically conscious Black athletes challenged America.