The representatives sent letters to Snyder, Commissioner Roger Goodell, Redskins sponsor FedEx and the other 31 NFL franchises, the Associated Press reports.
"Native Americans throughout the country consider the `R-word' a racial, derogatory slur akin to the `N-word' among African-Americans or the `W-word' among Latinos,” the letter states, according to the AP.
Leaders of the Congressional Native American Caucus -- Tom Cole, R-Okla., and Betty McCollum, D-Minn. -- were among those sending the letter.
A lawsuit challenging the Redskins' trademark protection continues to hang over the team, but Snyder vows to keep the name regardless.
"We will never change the name of the team,” he told USA Today recently. “As a lifelong Redskins fan, and I think that the Redskins fans understand the great tradition and what it's all about and what it means, so we feel pretty fortunate to be just working on next season.”