A flag that was carried into battle by a Black Union regiment during the Civil War is going up for auction in Pennsylvania on Thursday. The 127th United States Colored Infantry Regiment flag is one of 11 flags painted by 19th century artist David Bustill Bowser, an activist and son of a fugitive slave.  

The flag in question is the only known surviving flag of Bowser's, AP News reports. It depicts a Black soldier waving goodbye to Columbia, the white female representation of America, beneath a banner that reads, "We Will Prove Ourselves Men."

The Pennsylvania Historical and Museum Commission considers Bowser's works "the first widely viewed, positive images of African Americans painted by an African American."

Bowser had a successful banner and sign business in Philadelphia, and, after much opposition due to his race, was eventually chosen to design regimental flags for the 11,000 or so black union troops that trained at Camp William Penn, just outside Philadelphia. 

These men weren't allowed to join state troops, so federal Black regiments were formed, according to Joseph Becton of the African American Museum in Philadelphia.

Regiments received their flags after they completed their training and headed out to the battle field or other assignments.

“I do know that African American troops took special pride in these flags,” Dr. John David Smith, Professor of American History at University of North Carolina at Charlotte, told AP News in an email. “Not only did they represent their communities, but they underscored the honor and manhood that serving in the U.S. Army signified to them and the opportunity of Lincoln’s black soldiers in blue to help destroy slavery and to preserve the Union.”

Seven of Bowser's flags were given to West Point around the year 1900, but were destroyed in the 1940s (although photos of the flags still exist).

The 127th Regiment’s battle flag will be auctioned off Thursday June 13 at Morphy Auctions in Denver, Pennsylvania.