For most of her life Debra Willett had a vague idea about who her grandfather was. She knew he had fought in France in World War I at some point.

But she didn’t grasp the importance of what her grandfather, who died in 1956, had accomplished until she began doing some genealogy research in 1998.

Sgt. Leander Willett served with the distinguished 369th Infantry Regiment, commonly known as the Harlem Hellfighters, the most celebrated regiment of Black soldiers during World War I. Unlike many Black soldiers who were limited to manual labor and custodial duties, the Harlem Hellfighters made it to the front lines. There were celebrated for their bravery, helping to change the perception of Black soldiers as inferior.

As time passed, however, the Hellfighters, who numbered in the thousands, were largely forgotten. Somehow, they did not maintain the same historical prestige as the Tuskegee Airmen, the country’s first Black aviation unit, or the Montford Point Marines, the first Black marines, though the Harlem Hellfighters preceded both groups.

Although they returned home to cheers after the war, the Hellfighters, their descendants say, carried the scars of brutal combat and, once the cheering had stopped, the disappointment of remaining second class citizens, subjected to racism and discrimination, in the very country they had served and defended.

“As I understand from my aunt and my father he never ever spoke about World War I,” said Ms. Willett, 63, who lives in Oyster Bay on Long Island. “My father thinks that the reason he didn’t speak about it was the fact that he was bayoneted and gassed and it left such a horrible impression upon him.”

She added that “because he was African American this was really nothing spoken about or celebrated.”

Until now. The Harlem Hellfighters, largely overlooked for more than a century, will be awarded a Congressional Gold Medal. The U.S. Senate recently passed legislation to give them the award, and President Biden is expected to sign the bill as early as this month.