Savannah, Ga. ? Thomas J. Woods joined the military after graduating from an all-black high school in 1950, when Jim Crow laws forced him to the back of buses and Savannah shop clerks would greet him with a surly, “What you want, boy?”

But in Marine Corps boot camp and then the front lines of the Korean War, the 18-year old saw the rigid color barriers of civilian life smashed in front of him as the military followed a mandate to end segregation of its ranks. That major social change, carried out in wartime, has echoes in today’s debate about whether to end a ban on gays serving openly.

On his first day of training, as the only black recruit among 42, Woods was stunned when an instructor ordered his platoon to treat him as an equal. They all wore green, the instructor barked, and they’d all bleed red.

“I said, ‘I don’t believe this,”‘ recalls Woods, 78, a retired postal worker in Fayetteville, Ga. “It gave me a lot of pride, that you are somebody. When you go in there, you think you’re nothing. Blacks were always last at everything.”

Thomas J. Woods, 78, sits Wednesday in his home in Fayetteville, Ga. The stories of Woods and other black veterans who served among the military’s first desegregated units during the Korean War offer an iconic history lesson amid the debate over whether gays should be allowed to serve openly in uniform.

The stories of Woods and other black veterans who served among the military’s first desegregated units during the Korean conflict may bear lessons at a time when Americans are debating an end to “don’t ask, don’t tell.” The 1993 policy that bars gays from serving openly in uniform has been challenged by a federal court and President Barack Obama and is under review by the Pentagon.

Though the military may now seem to lag behind America’s acceptance of gays in civilian life, the armed forces led the charge in ending racial segregation in the 1940s and ’50s.

Efforts to integrate the ranks began right after World War II, culminating with President Harry S. Truman signing a 1948 executive order banning racial discrimination in the military.

The job wasn’t finished until the Defense Department disbanded its last all-black units in 1954. Still, that was at a time when the modern civil rights movement was just building momentum. Five months earlier, the Supreme Court had issued its landmark ruling ordering an end to segregation in America’s public schools. Bus boycotts in Montgomery, Ala., began the following year.

In other words, the military succeeded with desegregation when a huge proportion of Americans remained hostile to the idea of blacks and whites sharing schools, lunch counters and water fountains — or barracks and foxholes.

“This was a huge change forced upon the American population coming of age,” said Steven Schlossman, a history professor at Carnegie Mellon University and co-author of the book “Foxholes and Color Lines: Desegregating the U.S. Armed Forces.” “Its challenge to Jim Crow was enormous and maybe a shock to many yo