(CNN) — Former San Francisco 49ers quarterback Colin Kaepernick — who became a lightning rod in 2016 when he refused to stand during the National Anthem to protest the police shootings of black guys and other social injustices faced by African Americans — comprehended that the tenth anniversary of his first pregame protest on societal media Wednesday. Kaepernick composed on Twitter,”Today marks the three year anniversary of the first time that I protested systemic oppression. I continue to work and stand with the folks in our struggle for liberation, even though those people that are trying to erase the movement! The movement has ever lived with the people!” A movie accompanying the tweet shows movies of African Americans being killed by police, including 12-year-old Tamir Rice. Additionally, it contains Kaepernick talking about the aim of his demonstration. Kaepernick protested on August 14, 2016 prior to a house preseason game against the Houston Texans. He hasn’t played at the National Football League since the 2016 year, when he sparked controversy by sittingthen hammered, before several 2016 NFL preseason and regular-season games Last week, the athlete-turned-activist published a 59-second movie on his Twitter accounts of him working out to show that he’s ready to perform again. In the movie, the words”Denied work for 889 times” flashed throughout the screen. “5 a.m., five days per week, for 3 years. Nevertheless prepared,” said Kaepernick, that played with the 49ers for six years. Kaepernick turned into a free agent in 2017. No staff offered him a contract, and that Octoberhe also filed a grievance from the league, accusing team owners of colluding to prevent him away from being signed. He also former teammate Eric Reid, who knelt with Kaepernick, settled their collusion grievances cases against the NFL in February.