When Walter White, the head of the N.A.A.C.P. from 1931 to 1955, wrote a piece for the Chicago Defender in 1948 about a recent trip he had taken to Germany to report on black troops stationed there, he reflected on one particular question Germans had asked him about America: “How can you talk about German racism as long as you maintain separate white and black armies?”

As a civil rights activist, White had posed that very question to the United States government time and again. And the answer he received repeatedly was frank: America functioned under Jim Crow and the military was no different.

For the 1.2 million black men who served in a segregated army during World War II, efficiency and bravery on the battlefield didn’t lead to the social changes they had hoped for. The gulf between America’s ideals and its realities hit home particularly hard for one group: the thousands of black occupation troops sent to a defeated Germany to promote democracy.

“The military was just as segregated as the Deep South,” said Richard Kingsberry, a retired Army lieutenant colonel who leads the National Association for Black Veterans, a veterans’ service organization. “They didn’t want blacks in leadership positions. They didn’t want blacks supervising other soldiers. They wanted to function as they did in the United States.”