Here's a look at some stars who have stood out among the crowd.
Women's soccer player Megan Rapinoe followed the example of San Francisco 49ers quarterback Colin Kaepernick by kneeling during the national anthem as a way to "keep the conversation going."
Megan Rapinoe was critical of teammate Hope Solo calling Sweden "a bunch of cowards" after the United States' loss in the Rio Olympics.
Megan Rapinoe was selected to the U.S. women's national team for the Rio Games as coach Jill Ellis went with a younger team.
The U.S. women's national team's filing against U.S. Soccer is the latest clapback in the growing recognition of and protest against the unequal treatment of female athletes, Allison Glock says.
Members of the U.S. women's national soccer team have filed a wage-discrimination complaint against the U.S. Soccer Federation, saying they're paid almost four times less.
