Almost four years have passed since former San Francisco 49ers quarterback Colin Kaepernick first protested against racial injustice in the United States by kneeling during the national anthem.
In the time since, many players have joined Kaepernick in protesting, while Kaepernick himself - after opting out of his 49ers contract - remains without a team.
There has been criticism by US President Donald Trump, rules to fine teams whose players kneel introduced - and then put on hold - and even a lawsuit.
But only now has the NFL made a U-turn on its stance, saying it was "wrong" for not allowing players to protest.
- 'People realise NFL hasn't listened'
- From 2017: Kaepernick and a movement dividing a country
- The fashion stylist supporting Kaepernick in his fight against racial injustice
It comes after the death of unarmed African American George Floyd, who died on 25 May while being restrained by a white police officer in Minneapolis. His death has sparked protests across the US and worldwide.
BBC Sport takes a look back at the timeline of Kaepernick's protests.
26 August, 2016
What happened? Kaepernick sits on the bench during the national anthem before the 49ers' pre-season home game against the Green Bay Packers.
"I am not going to stand up to show pride in a flag for a country that oppresses black people and people of colour," he tells media.
What did the NFL say? "Players are encouraged but not required to stand during the playing of the national anthem."
1 September, 2016
What happened? Kaepernick changes his method of protesting to kneeling while the anthem is played before the 49ers play the San Diego Chargers. He is joined in the stance by team-mate Eric Reid.
Earlier that week, then Republican presidential candidate Donald Trump says: "I think it's a terrible thing, and you know, maybe he should find a country that works better for him."
7 September, 2016
What did the NFL say? NFL commissioner Roger Goodell breaks his silence, saying: "I don't necessarily agree with what he is doing.
"I support our players when they want to see change in society, and we don't live in a perfect society.
"On the other hand, we believe very strongly in patriotism in the NFL. I personally believe very strongly in that."
11-12 September, 2016
What happened? On the opening weekend of the NFL season, Kaepernick and Reid kneel during the anthem. Team-mates Antoine Bethea and Eli Harold display Black Power salutes, as do two members of the opposing LA Rams team. Similar protests are held by NFL players across the league.
Trump says their actions show a "great lack of respect and appreciation" for the country.
21 September, 2016
What happened? Kaepernick reveals he has received death threats over his refusal to stand for the national anthem.
1 March, 2017
What happened? Kaepernick's agent tells NFL teams he will opt out of his contract with the 49ers, a move made possible in a restructuring of his contract the previous October.
24 September, 2017
What happened? Days after now president Donald Trump says players who kneel should be fired, players from several teams protest during the national anthem, while others remain in the dressing room.
15 October, 2017
What happened? Still unsigned after leaving the 49ers, Kaepernick files a grievance against NFL team owners he believes are conspiring not to hire him because of his protests against racial injustice.
23 May, 2018
What happened? The NFL introduces a rule whereby teams will be fined if players kneel for the US national anthem. Players who do not stand for the Star-Spangled Banner can stay in the locker room until it has been performed.
What did the NFL say? Goodell says: "We want people to be respectful to the national anthem.
"We want people to stand - that's all personnel - and make sure they treat this moment in a respectful fashion. That's something we think we owe.
"We have been very sensitive in making sure we give players choices, but we do believe that that moment is important and one we are going to focus on."
19 July, 2018
What happened? The policy to fine teams if players kneel for the anthem is put on hold.
The NFL and NFL Players' Association (NFLPA) issue a joint statement saying they were working on a "mutual resolution".
3 September, 2018
15 February, 2019
What happened? Kaepernick reaches a settlement with the NFL over his 'collusion' case against team owners.
What did the NFL say? In a joint statement, the NFL and Kaepernick say: "The parties have decided to resolve the pending grievances. The resolution of this matter is subject to a confidentiality agreement so there will be no further comment by any party."
7 August, 2019
What happened? Kaepernick says he is "still ready" to play in the NFL despite being without a contract for 889 days.
10 October, 2019
What happened? Singer Rihanna says she declined an invitation to headline the Super Bowl half-time show in support of Kaepernick.
What did the NFL say? It refuses to comment.
13 November, 2019
What happened? The NFL arranges a private workout for Kaepernick on the following Saturday that all 32 teams are invited to attend.
What did the NFL say? In a statement now deleted from their website, it said several teams had asked about Kaepernick's readiness to play.
17 November, 2019
What happened? Kaepernick chooses not to attend an NFL-arranged private workout, instead holding his own session at a high school to allow media to attend.
He said he wanted "transparency", claiming the NFL denied media access to its own planned workout in Atlanta.
What did the NFL say? "We are disappointed that Colin did not appear for his workout.
"Colin's decision has no effect on his status in the league. He remains an unrestricted free agent eligible to sign with any club."
29 May, 2020
What happened? Kaepernick defends protests after the death of George Floyd.
"When civility leads to death, revolting is the only logical reaction," Kaepernick says. "The cries for peace will rain down, and when they do, they will land on deaf ears, because your violence has brought this resistance. We have the right to fight back! Rest in power George Floyd."
5 June, 2020
What happened? NFL stars including Patrick Mahomes and Odell Beckham Jr call on the NFL to "condemn racism and the systemic oppression of black people".
What did the NFL say? "This is a time of self-reflection for all - the NFL is no exception. We stand with the black community because Black Lives Matter."
6 June, 2020
What happened? The NFL says players should be allowed to protest during the national anthem.
What did the NFL say? Goodell says: "We were wrong for not listening to NFL players earlier and encourage all to speak out and peacefully protest.
"We, the National Football League, believe black lives matter. Protests around the country are emblematic of the centuries of silence, inequality and oppression of black players, coaches, fans and staff.
"I will be reaching out to players who have raised their voices and others on how we can improve."