"In the late 1930s, in rural Georgia, a former slave told his grandson a story about a case of racial injustice that had occurred three decades earlier and gone all the way to the White House"

NYT:

the city’s mayor and other white citizens had accused about 20 unidentified black soldiers stationed nearby, at Fort Brown, of having shot up the town.

“Dastardly Outrage by Negro Soldiers” read the headline in The Brownsville Herald the next day.

The soldiers, members of the segregated First Battalion, 25th Infantry (Colored), as it was known, professed their innocence. Their white commander said he believed that all the black soldiers were in their barracks at the time of the shooting, and that their rifles did not appear to have been fired.

But the white citizens said they had seen black soldiers on the street firing indiscriminately, and they produced spent shells from Army rifles to support their version of events. Despite evidence that the shells had been planted, investigators accepted that account.

President Theodore Roosevelt, as commander in chief, promptly and summarily discharged all 167 members of the unit, asserting that they had engaged in a “conspiracy of silence” by refusing to confess or incriminate fellow soldiers. A United States Senate inquiry two years later upheld his action.

The grandson who heard this account, William Baker, would grow up to become a lieutenant colonel in the Army, and by 1972 he had been assigned to the Pentagon to work in the newly minted Army Equal Opportunity Program, for which he helped develop a system for black soldiers to express their concerns to the chain of command.

...

Hearing about the reopened investigation, and remembering the story his grandfather had told him, Colonel Baker asked for and received permission to help.