Posters of Rapinoe in the New York City subway system were scribbled with derogatory slurs, prompting an investigation.
A letter to the team says senators want to look at “challenges women face on and off the field,” likely including the issue of equal pay.
Large crowds gathered to celebrate the United States' Women's World Cup win in New York City, where Megan Rapinoe gave a powerful speech.
Wambach, who played in the 2003, 2007, 2011 and 2015 World Cups, said she's proud of the U.S. national team for taking a stand.
Conversations about a pay gap arose leading up to the World Cup as 28 members of the USWNT filed a lawsuit against U.S. Soccer.
She joined Anderson Cooper on CNN and talked for 30 minutes about a wide range of topics.
“I think there’s a part in this for everybody to do … and now it’s time for that action,” Rapinoe said.
After winning the Women's World Cup, the United States continued to celebrate on their return home.
Some NWSL players are paid just $16,538 a season, with World Cup winners Anson Dorrance and Shannon Higgins-Cirovski calling for change.