Colin Kaepernick

As the NFL kicks off the regular season, it will do so with a protester in its midst. San Francisco 49ers quarterback Colin Kaepernick, who has chosen not to stand during the national anthem through the preseason, promises more of the same when his team hosts the Los Angeles Rams on Monday Night Football.

There has been plenty of backlash against Kaepernick, but he says he is committed to standing up (or sitting down, as the case may be) for what he believes in. He tried to clarify just exactly what he is protesting in an interview with in late August.

"I am not going to stand up to show pride in a flag for a country that oppresses black people and people of color," Kaepernick told NFL Media. "To me, this is bigger than football and it would be selfish on my part to look the other way. There are bodies in the street and people getting paid leave and getting away with murder."

Kaepernick is not the first – and likely won't be the last – to use his athletic stage to make a political statement. While the Seahawks stood during the national anthem and locked arms with each to show racial unity Sunday in Seattle, players on other teams chose to kneel or raise fists. Since 2014, black athletes, often through the "Black Lives Matter" movement, have used their platforms to protest.

But American athletes have chosen to bring politics to the baseball field, basketball court and Olympic track throughout history. Following is a look at some of the more renowned demonstrations:

Tommie Smith And John Carlos

Wikimedia Tommie Smith And John Carlos

Likely the most iconic protest by athletes, Tommie Smith and John Carlos held their black-gloved fisted arms high when the "Star Spangled Banner" was played after they finished first and third, respectively, in the 200 meters at the Mexico City Olympic Games in 1968. The two also accepted their medals shoeless, wearing black socks to represent black poverty, and Smith wore a black scarf to represent black pride. Interestingly, the silver medalist, Australia's Peter Norman, stood in solidarity with the Americans and all three wore "Olympic Project for Human Rights" badges. It was Norman who suggested that after Carlos forgot his pair of black gloves that the Americans each wear one. After the protest, the IOC demanded that the USOC suspend Smith and Carlos and remove them from the Olympic Village. The USOC initially declined by later complied when the IOC threatened to eject the entire U.S. contingent.

Mahmoud Abdul-Rauf

Getty Images Mahmoud Abdul-Rauf

The Denver Nuggets guard refused to stand during the national anthem in 1996, calling the it "a symbol of oppression and tyranny." Abdul-Rauf, formerly known as Chris Jackson before converting to Islam, was suspended for one game for the protest and was traded after the season. The protest likely cost Abdul-Rauf part of his NBA career, which ended at age 31, after stints in Sacramento and Vancouver. Among the best free-throw shooters in NBA history (90.5 percent during the regular season), Abdul-Rauf averaged 14.6 points, including 19.2 during the 1995-96 season.

LeBron James

Getty Images LeBron James

As part of the Black Lives Matter movement, James led a group of NBA players in wearing T-shirts that read "I Can’t Breathe," in memory of Eric Garner, a black man who died while a police officer held him in a chokehold in 2014. Kevin Garnett, Jarrett Jack and Kyrie Irving joined James in the initial protest, which spread throughout the league.

Carlos Delgado

Getty Images Carlos Delgado

Born in Puerto Rico, Delgado had an MLB that spanned 17 seasons, and throughout he was (and still is) known as a peace activist. In his most public protest, Delgado opted to stay in the dugout when "God Bless America" was played during the seventh-inning stretch as a way of showing his discontent with the U.S.'s occupation of Iraq. (Part of his protest was also regarding the Navy's weapons testing on the Puerto Rican island of Vieques.) He believed that the song had become associated with a war he didn't believe in. Though he called it "the stupidest war ever," Delgado, who played for Toronto during his year of protest, did stand for "God Bless America" after being traded from Florida to the New York Mets in 2006.

Ariyana Smith

WQAD Ariyana Smith

Though you've probably never heard of Smith, she is the author of one of the most poignant protests in sports history. A basketball player for Division III Knox (Ill.) College, Smith in 2014 walked onto the basketball court with her hands raised and dropped to the floor for four-and-a-half minutes during the playing of the "Star Spangled Banner." The protest was in honor of Michael Brown, who was killed by police in Ferguson, Mo. His body was left on the street for four-and-half hours. Smith was initially suspended, but the school reinstated her after a week.

Megan Rapinoe

Getty Images Megan Rapinoe

In an effort to stand (or sit) in solidarity with Kaepernick, Seattle Reign midfielder Megan Rapinoe kneeled during the national anthem when her National Women's Soccer League team played in Chicago on Sept. 4. Rapinoe said she plans to continue to kneel, but just a few days later, in an effort to prevent any discomfort for their fans, the host Washington Spirit moved up the playing of the "Star Spangled Banner," to when teams were not on the field. Rapinoe said she was "saddened" by the Spirit's decision.

"To willingly allow anyone to hijack this tradition that means so much to millions of Americans and so many of our own fans for any cause would effectively be just as disrespectful as doing it ourselves," the Spirit said in a statement.