The US Army set aside the court-martial convictions from a century ago of 110 African American soldiers, including 19 who were executed, saying they were denied fair trials in a landmark acknowledgement of official racism in America.

The Army Board for Correction of Military Records overturned the convictions, restoring their service records as having concluded honorably and making their descendants eligible for military benefits, the Army said in a statement.

“After a thorough review, the Board found that these Soldiers were wrongly treated because of their race and were not given fair trials. By setting aside their convictions and granting honorable discharges, the Army is acknowledging past mistakes and setting the record straight,” Army Secretary Christine Wormuth said in a statement.

The reversal comes as right-wing politicians and parents banning books dealing with race and slavery in schools and the U.S. Supreme Court striking down affirmative action policies intended to promote racial equality in university admissions.

The Army convictions arose out of the Houston Riots of Aug. 23, 1917, an outbreak of violence that followed months of racist taunts against Black soldiers of the 3rd Battalion, 24th Infantry Regiment. They were also known as the Buffalo Soldiers, a name of Native American origin that was given to Black regiments in the Army dating to the 19th Century.

On that day Black soldiers guarding a military property were subjected to racist slurs and physical attacks, the Army said. About 100 fellow Black soldiers came to their aid and marched into the city, where ensuing violence killed 19 people, the Army said.

Army courts-martial eventually convicted 110 Black soldiers, including 19 who received the death penalty, in a process that historians determined contained “numerous irregularities,” the Army said.

The review board found the court-martial cases were so fundamentally unfair that all the convictions should be set aside.

The mass execution of 19 soldiers was the largest carried out by the Army of American soldiers in history, the Army said.

The first group of men was hung in secret within one day of sentencing, the Army said.

The convictions were overturned after the South Texas College of Law petitioned the Army to review the cases, prompting requests from retired officers to grant clemency to all 110 soldiers, the Army said.