Colin Kaepernick, the former San Francisco 49ers quarterback whose refusal to stand during the national anthem in protest at social injustice helped kick off a new age of athlete activism, said on Wednesday that he’s completed his pledge to donate $1m to organizations serving oppressed communities in the United States.

In a final 10-day push to reach the million-dollar goal, Kaepernick had issued a challenge to his friends from the worlds of sports and entertainment to donate $10,000 to a cause of their choice, which he then matched with another $10,000.

On Wednesday, Kaepernick said the goal was met after he matched a $10,000 donation by recording artist Usher to the Helping Oppressed Mothers Endure (Home) charity in Lithonia, Georgia.

“Day 10 of my #10for10! Thank you @usher for choosing H.O.M.E. for the #MillionDollarPledge,” Kaepernick said Wednesday on Twitter. “We’re donating $10k each to them for a total of $20k! It’s been an honor to work for the people and donate $1 mil to orgs fighting for social justice!”

I am happy to announce I have completed my #MillionDollarPledge. For the final #10for10 joining me is my brother @usher! He is donating $10k to match my $10k for $20k for H.O.M.E from Lithonia, GA. Head to https://t.co/aK6dK9NZZA for a complete list of my Million Dollar Pledge! pic.twitter.com/WiSAJePPcB — Colin Kaepernick (@Kaepernick7) January 31, 2018

Added Usher in a video posted to Kaepernick’s Twitter feed: “This was an opportunity to do something major, and you did it. You have raised $1 million. I’m happy to be a part of the completion of that $1 million. Everyone that has done something around this is amazing. This is a collaborative effort. As a result of us helping each other, we all become stronger.”

Other celebrities who donated amid Kaepernick’s final push included athletes Steph Curry (to United Playaz), Kevin Durant (to Silicon Valley De-Bug) and Serena Williams (to Imagine LA) along with recording artists Snoop Dogg (to Mothers Against Police Brutality), Meek Mill (to Youth Service, Inc) and TI to (Angel by Nature).

The previous $900,000 in donations, all from Kaepernick, were earmarked for charities across the country addressing a broad range of social issues including homelessness, education, community-police relations, criminal justice reform, inmates’ rights, at-risk families and reproductive rights.

Highlights included $50,000 donations to Somalia Famine Relief and Life After Hate, an educational and rehabilitative organization started by former members of hate groups in Chicago. He also made $33,000 gifts to a pair of New York charities – the Lower East Side Girls Club and 100 Suits for 100 Men – and at least eight more separate gifts of $25,000.

Kaepernick first pledged to donate $1m to community projects in September 2016, shortly after he first took a knee during the national anthem before a pre-season game against the San Diego Chargers. In addition, he promised to donate all proceeds from his 2016 jersey sales to charity.

The six-year NFL veteran, who led San Francisco to Super Bowl XLVII before the league caught up to his running-and-passing style, opted out of his contract with the 49ers in March but has remained unsigned. A number of NFL players, including the Seattle Seahawks cornerback Richard Sherman, believe he is being blackballed by NFL teams for his political protest.

Sherman told ESPN last year that Kaepernick’s remaining unsigned has little to do with the quality of his play and everything to do with his national anthem protest of last year. “It has nothing to do with football. You can see that,” Sherman said.

Asked why Kaepernick had not yet been picked up by a new team, Sherman said: “It’s difficult to see because he’s played at such a high level, and you see guys, quarterbacks, who have never played at a high level being signed by teams. So it’s difficult to understand.”

Kaepernick completed 59.2% of his passes, averaged 6.8 yards per attempt and threw 16 touchdowns with four interceptions in 12 games for the 49ers in the 2016 season, his last in the league. But his refusal to stand for the national anthem in protest of police brutality and racial injustice became a far bigger story than his on-field performance.