The powerful stance ended Kaepernick's career. Despite pundits accepting the San Francisco 49ers quarterback was good enough to keep going in the NFL, he has not made another appearance since that 2016 season.
To anyone with an ounce of common sense, it had to be because of his politically-motivated position which caused huge controversy in a country that demands honour to the flag. But NFL teams said otherwise.
Everyone in the league denied Kaepernick's commitment to justice had anything to do with the abrupt end to his time as an NFL play-caller, instead suggesting he didn't have the skills franchises were looking for.
But in a column for CNN on the weekend, the NFL's vice president of communications at the time of Kaepernick's headline-grabbing move called bulls***. NFL owners were scared of the drama he would bring, even though on talent alone he was deserving of a spot on someone's roster.
"No teams wanted to sign a player — even one as talented as Kaepernick — whom they saw as controversial, and, therefore, bad for business," Joe Lockhart wrote.
"An executive from one team that considered signing Kaepernick told me the team projected losing 20 per cent of their season ticket holders if they did. That was a business risk no team was willing to take, whether the owner was a Trump supporter or a bleeding-heart liberal (yes, those do exist).
"As bad of an image problem it presented for the league and the game, no owner was willing to put the business at risk over this issue.
"For many owners it always came back to the same thing. Signing Kaepernick, they thought, was bad for business."
'I TOLD YOU IT WAS A LIE'
Award-winning journalist turned TV commentator Michael Wilbon said this was an admission of what everybody already knew.
In an emotional episode of his Pardon The Interruption show on ESPN alongside Tony Kornheiser, Wilbon let rip at everyone in the NFL responsible for pushing the "lie" that tried to convince people Kaepernick's protest had nothing to do with his being cast into the wilderness.
"What did I say to you on this show on our set in Washington DC the first day Colin Kaepernick was let go?" Wilbon told Kornheiser.
"I told you he would not be back in the league. I told you that it was a lie.
"I told you the NFL owners were lying. I didn't stutter or stammer over any of that for years.
"I know at the beginning you thought I was going too far and then slowly as this went on and on and on, you understood where I was coming from.
"I don't want to hear any statement from the league when this is what Colin Kaepernick was objecting to. This whole last weekend, this whole last week, what we saw in Minneapolis … this is why he and others took a knee.
"I hope many more players take a knee when the NFL resumes, whenever that is.
"Colin Kaepernick looks pretty good right now because he got it right. He said, 'This is a systemic problem, it is not going away, it is ongoing and I am objecting to this' and the NFL said, 'We don't want you'.
"Then they lied. And they lied month after month for a couple of years about why he wasn't in the league. They ought to be embarrassed by this column, don't know if they are."
President Donald Trump said NFL owners should fire anyone who refused to stand for the anthem, questioning whether they should even be allowed to live in the United States.
Anyone who took a knee during the Star Spangled Banner was a "son of a b**ch", Trump said, while his Vice President Mike Pence walked out of an NFL game between the Niners and Indianapolis Colts when players copied Kaepernick's protest.
As Wilbon complains, NFL owners were complicit in allowing this behaviour and rhetoric to go unchecked.
The "statement from the league" he refers to is what was released by NFL commissioner Roger Goodell in the wake of the terrifying scenes that have gripped America.
"The NFL family is greatly saddened by the tragic events across our country. The protesters' reactions to these incidents reflect the pain, anger and frustration that so many of us feel," the statement read.
"As current events dramatically underscore, there remains much more to do as a country and as a league. These tragedies inform the NFL's commitment and our ongoing efforts. There remains an urgent need for action. We recognise the power of our platform in communities and as part of the fabric of American society. We embrace that responsibility and are committed to continuing the important work to address these systemic issues together with our players, clubs and partners."
These words rang hollow in the eyes of many given how Kaepernick was tossed aside.
Houston Texans wide receiver Kenny Stills tweeted "save the bulls***", while film director Ava DuVernay wrote: "Shame on you. This is beyond hollow + disingenuous."
In his column, Lockhart suggests the governing body did what it could to help Kaepernick but it was team owners who were the biggest barrier to his career continuing.
What's certain now is Kaepernick was right all along. A recent front page of the Houston Chronicle put it best when illustrating why.
