The deal unveiled by Nike and the former San Francisco 49ers quarterback was a trending topic on Twitter and other social networks, with some fans urging a boycott of the company's clothes and sneakers - even burning and cutting out the signature swoosh logos on their gear.
Others pushed back, saying the backlash against Nike showed the polarizing debate has morphed well beyond whether NFL players should be allowed to demonstrate for social causes while the national anthem plays in stadiums before games.
Here's what you should know about Kaepernick's career:
Kaepernick played college football for Nevada.
April 29, 2011
Drafted by the 49ers in the second round of the 2011 NFL Draft.
Kaepernick named starting quarterback in Super Bowl XLVII.
August 26, 2016
Before a game against the Green Bay Packers, Kaepernick knelt on the field during the national anthem.
He said his peaceful protest was a grievance against the oppression of African Americans and other people of color.
A deep dive into the 'Take a Knee' controversy
March 3, 2017
Kaepernick opted out of his contract with the 49ers.
October 16, 2017
The former quarterback filed a grievance against the NFL. The grievance was filed under a collective bargaining agreement against NFL owners for allegedly colluding to keep him out of the league.
September 3, 2018
Nike signed an endorsement deal with Kaepernick. A new ad gained instant attention of people on both sides of the aisle.
"We believe Colin is one of the most inspirational athletes of this generation, who has leveraged the power of sport to help move the world forward," Gino Fisanotti, Nike's vice president of brand for North America, told ESPN.
The Associated Press contributed to this report.