Redskins President Bruce Allen said in a letter to Senate Majority Leader Harry Reid on Saturday that the football team's nickname is "respectful" toward Native Americans.
On Thursday, half the U.S. Senate urged NFL Commissioner Roger Goodell to change the Washington club's name, saying it is a racist slur and it is time to replace it.
The franchise responded by releasing Allen's letter.
"Our use of 'Redskins' as the name of our football team for more than 80 years has always been respectful of and shown reverence toward the proud legacy and traditions of Native Americans," he wrote.
The letter references research that "the term Redskins originated as a Native American expression of solidarity." It notes that the team's logo was designed by Native American leaders and cites surveys that Native Americans and Americans as a whole support the name.
Redskins owner Daniel Snyder has refused to change the name, citing tradition, but there has been growing pressure including statements in recent months from President Barack Obama, lawmakers of both parties and civil rights groups. Last month, Reid took to the Senate floor to say Snyder should "do what is morally right" and change the name.
In a letter Thursday, 49 senators mentioned the NBA's quick action recently to ban Los Angeles Clippers owner Donald Sterling for life after he was heard on an audio recording making offensive comments about blacks. They said Goodell should formally push to rename the Redskins.
"We urge you and the National Football League to send the same clear message as the NBA did: that racism and bigotry have no place in professional sports," read the letter, which did not use the word "Redskins."
Sen. Bill Nelson of Florida wrote his own letter saying he doesn't believe that retaining the Redskin name "is appropriate in this day and age."
In a written response Thursday, NFL spokesman Brian McCarthy said "the intent of the team's name has always been to present a strong, positive and respectful image."
Reid and Sen. Maria Cantwell of Washington led the letter-writing effort. All senators on the letter are Democrats. Cantwell spokesman Jared Leopold said Republicans were not asked to participate.
The senators noted that tribal organizations representing more than 2 million Native Americans across the U.S. have said they want the Redskins name dropped.
Despite federal laws protecting their identity, "Every Sunday during football season, the Washington, D.C., football team mocks their culture," they wrote. "The NFL can no longer ignore this and perpetuate the use of this name as anything but what it is: a racial slur."