In January 1965, 21 black players came to New Orleans for the American Football League’s All-Star Game. Upon arriving at the airport, they couldn’t find taxis willing to take them downtown. And in the French Quarter, they found that restaurants and nightclubs wouldn’t seat them either.

So they decided to boycott the game. “Someone had to take a stand and stop players from being treated as second-class citizens,” defensive tackle Ernie Ladd recalled.

It’s time for our present-day professional athletes to take a stand against racism in our criminal justice system, which continues to treat African-Americans as second-tier human beings. And that means sitting out, at least for a game or two.

To be fair, several athletes have made public protests about police killings of unarmed black men in Ferguson, Missouri, and Staten Island, New York. Last month, five members of the St. Louis Rams football team walked onto the field making the “hands-up” gesture that has galvanized demonstrators since the shooting of Michael Brown by officer Darren Wilson. 

And at Monday night’s game between the Cleveland Cavaliers and the Brooklyn Nets, LeBron James and five other players donned “I Can’t Breathe” warm-up shirts in memory of Eric Garner, the Staten Island man who was choked to death. The following night, Kobe Bryant and all but one of his fellow Los Angeles Lakers wore the same shirt before their game against the Sacramento Kings.

Soon the shirts will devolve into a style statement, absorbed into the vortex of social media. That's why the players should choose action over words.

As the black football players departed for the New Orleans airport in 1965, they noticed that some of the same taxis that had refused to pick them up were now offering them rides. The city desegregated its public facilities rapidly after that, convincing pro football authorities to award New Orleans its own franchise—the Saints—the following year.

Two years later, in 1968, black athletes threatened to boycott the Olympic Games in Mexico City to protest racial discrimination in the United States. Most of them eventually decided to participate, but a few prominent sportsmen—including Lew Alcindor, the UCLA basketball star—sat out.

“We have been a racist nation,” explained Alcindor, who would soon change his name to Kareem Abdul-Jabbar, “and my decision not to go to the Olympics is my way of getting the message across.”

Medal winners Tommie Smith and John Carlos would send a similar message on the victor stand at Mexico City, raising their fists in black-power salutes. But if you look closely at the iconic photo of their protest, you’ll see that the third medalist—a white Australian named Peter Norman—was also wearing a badge supporting the “Olympic Project for Human Rights.”

That project was organized by several white members of the American rowing team from Harvard. “Each of us had come to feel a moral commitment to support our black team-mates in the effort to dramatize the injustices and inequities which permeate our society,” the rowers declared. “Working to correct racial injustices is the undeniable task of all athletes and all men, black and white.”

That’s a bi-racial spirit we haven’t seen in the athletes' protests about Ferguson and Staten Island, which have featured black players almost exclusively. Where are the voices of white athletes, standing up for African-Americans who face violence and intimidation from the people paid to enforce the law?

Consider the recent Justice Department report about the Cleveland police,  where 12-year old Tamir Rice was recently killed when an officer mistook Rice’s toy gun for a real one. For years, the justice department found, Cleveland police have stalked, beaten, and Tasered African-Americans with reckless impunity. In one notorious instance, police even fired at a black man who was escaping from a kidnapping in his boxer shorts.

I’m proud of players like Cleveland Browns safety Johnson Bademosi, who wore a protest shirt during warmups before his team took on the Indianapolis Colts last Sunday. I only wish that Bademosi—and his white teammates—would sit out for a few games, like their forbears did in the 1960s.

Perhaps players could demand that special prosecutors be appointed for all police-related deaths, as some reformers have suggested. Or they could simply ask that Americans stop watching sports, for a week or even just a day, and start looking at the issues that are staring all of us in the face.

That’s what Ernie Ladd and other players made America do in 1965, when their boycott forced the AFL to move its All-Star Game to Houston. But the new site had its own ugly racial history, which stirred especially uncomfortable memories for Ladd. A few years earlier, a black sportswriter had pleaded for him to sit out a game in Houston to protest the segregation of African-American spectators in the end zone. “Stand up and show some guts,” the sportswriter had told him. Ladd came to regret the decision, and the 1965 All-Star Game was his chance to make things right.

Let’s hope contemporary athletes can muster the same courage. Their employers—and many of their fans—won't be happy. But future generations will thank them for it.