On Dec. 29, 1890, the U.S. Army's 7th Cavalry opened fire on hundreds of Native Americans in one of most shameful and bloody acts of violence against indigenous people in American history.

"I have never heard of a more brutal, cold-blooded massacre than that at Wounded Knee," wrote Maj. Gen. Nelson Miles, who served as an Army commander during the Indian Wars. A majority of the fatalities were women and children.

For these acts at Wounded Knee, 20 Medals of Honor were awarded to the soldiers of the 7th Cavalry. Over a century later, some lawmakers are trying to strip those awards away.

On Wednesday, two Senate Democrats unveiled legislation to strip the Medals of Honor from the American soldiers who participated in the Wounded Knee Massacre. The bill, known as the "Remove the Stain Act," was announced Wednesday by Elizabeth Warren of Massachusetts and Jeff Merkley of Oregon, and serves as the Senate equivalent of a House bill introduced earlier this year by Reps. Deb Haaland, D-N.M., and Denny Heck, D-Wash.

In a statement, Warren said the bill was "a step toward righting wrongs against Native peoples."

Earlier this year, President Donald Trump invoked the Wounded Knee massacre to mock Warren for a controversial decision to take a DNA test to ascertain Native American ancestry.

In December of 1870, Chief Big Foot, leader of the Minneconjou Lakota, was leading his people to refuge in South Dakota when they were intercepted by the U.S. Army. They surrendered, were brought to an encampment at Wounded Knee Creek and surrounded by 470 soldiers and their formidable artillery, according to historian Mark Hirsch.

Precise details on the battle have been difficult to ascertain, but historians believe that on Dec. 29, a disagreement broke out as American soldiers attempted to disarm Big Foot's men; a shot was fired, and then the Americans attacked. Estimates for the number of deaths range from fewer than 200 to more than 400, but there's consensus that most of the Native Americans killed were women and children.

Among the victims, Miles recalled in a November 1891 letter, were "women with little children on their backs, and small children powder-burned by the men who killed them being so near as to burn the flesh and clothing with the powder of their guns, and nursing babies with five bullet holes through them."

The Medals of Honor awarded to soldiers at Wounded Knee have long been criticized as unjustified decorations for a lopsided massacre where little fighting occurred, and where evidence has pointed to many U.S. soldiers wounded by their own men rather than by Lakota Indians.

Many of the award citations simply noted "gallantry" and "bravery" with few specific details, contradicted claims or acts that did not appear especially notable, according to the Nebraska Historical Society.

Cpl. Paul Weinert received the medal for firing a howitzer into an Indian position in a ravine. The fire "undoubtedly" killed and wounded women and children, the society wrote. Weinert said he was raked by Native gunfire that was "coming like hail," but other sources suggest only three or four Lakotas were there, the society said.

One soldier's draft recommendation noted a kitchen hand received the medal because his act of bravery was "voluntarily leaving his work as cook." Another appeared to receive the award for staying on with the campaign after his enlistment ended, the society said.

Historians have also pointed to the unusually high number of awards from a moment of armed resistance that lasted as long as one hour. The Civil War battle at Antietam, the bloodiest day in U.S. history, resulted in the same number of Medal of Honor recipients.

The Medal of Honor was given more liberally in the 19th century, especially in the Civil War, when it was the only authorized medal. It wasn't until 1918, following a review and purge of more than 900 medals, that Congress tightened the criteria for receiving the medal for conspicuous gallantry. But that purge did not include the 20 Medals of Honor given for action at Wounded Knee.

As the Medal of Honor gradually evolved to become the nation's most rare and distinguished military award, Native Americans have fought to have them rescinded for participants in the massacre. In 2001, the Cheyenne River Sioux Tribe passed a resolution requesting the U.S. government revoke the medals. The National Congress of American Indians has issued resolutions dating back to 1997 that make the same request.

Later, in 2019, the NCAI issued another resolution that supported Reps. Haaland and Heck's House bill.

Congress issued a formal apology in 1990 that expressed "deep regret on behalf of the United States to the descendants of the victims and survivors and their respective tribal communities." It did not, however, offer any form of reparations to these individuals, the Associated Press reported.

Upon unveiling the new House legislation in June, Haaland said she hoped that it "shows the continued work and strength of the Native American people who have fought for over a century for the United States to acknowledge the genocide of our people that has taken place on this soil," Stars and Stripes reported.

"We have a responsibility to tell the true story of the horrific Wounded Knee Massacre," Merkley said in a statement on Wednesday. "We cannot whitewash or minimize the dark chapters of our history, but instead must remember, reflect on, and work to rectify them. The massacre of innocents could not be farther from heroism, and I hope this bill helps set the record straight."