San Francisco 49ers cheerleader takes a knee during national anthem

The NFL passed a new rule in May that banned players from sitting or taking a knee during the anthem but allowed players to stay in the locker room if they wanted. Then last month, the NFL and the National Football League Players Association agreed to halt enforcement of the rule while the two sides worked on a resolution, which isn't expected to happen this season.

In 2016, former 49ers quarterback Colin Kaepernick was the first pro athlete to take a knee during the national anthem at NFL games in protest over police brutality and racial and social injustice.

He was not re-signed after the season ended and hasn’t played pro football since, but his actions sparked a movement that involved dozens of athletes and cheerleaders across the nation in the years following.