The four brass service medals are nestled in velvet. They're no big deal, Louis Diggs says, no different from those received by thousands of other veterans of the Korean War.

But this small handful of metal and cloth represents enormous changes in the way the U.S. military treats African-American soldiers, and that's why Diggs' medals are on display at the Lewis Museum.

In 1950, Diggs joined an all-black Maryland National Guard unit, the 231st Transportation Truck Battalion. Several months later, it became the first Guard unit in the nation to be shipped to Korea.

"When our Guard unit traveled through Virginia, we could not stop on the road to get anything to eat," says Diggs, 73, of Owings Mills. "No one would serve us."

Overseas, the indignities continued: There were separate lines for white and black soldiers at the Army PX. Black soldiers ate last. When black colleagues in other units paraded past top commanders, the band played "Old Black Joe" for them. Marching tunes were played for white soldiers.

But that wasn't the worst part.

"If you were driving down a road and you saw a tank coming at you, you'd get out of the way fast," Diggs says. "Even if they were on our side. Otherwise, they'd fire at you."

There were few opportunities for ambitious young black men in Baltimore in the 1950s, so Diggs re-enlisted. And kept re-enlisting until he'd spent 20 years in the Army, eventually achieving the rank of sergeant first class. Diggs was posted to Japan, Germany and, for several years, Baltimore, where he had a dream job overseeing ROTC programs at Morgan State University. Now, he writes history books about black families who lived in Baltimore County.

Slowly, things began to change, as integration policies ordered in the 1940s by then-President Harry S. Truman took effect. In 1955, Diggs' formerly all-black National Guard unit was integrated and became the 229th Transportation Battalion. During the Vietnam War, he said, racial discrimination in the Army was finally put to rest.

"Things changed when we got to know each other," he said. "It's important for young people today to know what the older veterans went through."

As Diggs says, his service medals are identical to those worn by thousands of other Army veterans.

And that's the point.