That's when blacks were first allowed into the Corps, but had to train at a segregated base at Montfort Point, N.C. Some of those old-timers joined younger Marines at the reunion in Las Vegas.
American blacks had to fight for the right to fight in segregated units in World War II. It wasn't just the Montfort Point Marines, but also the famed Tuskegee Airmen and Buffalo Soldiers. Blacks continued to sign up in great numbers for Korea, Vietnam and beyond.
Retired commander Gregory Black was a Navy diver for most of his 21 years in the service. In Maryland, he runs a year-old Web site, BlackMilitaryWorld.com, which chronicles what African-Americans have contributed to the armed services of this country.
"Once we joined the military, when the call went out that we had to fight, we fought," he told CBS News correspondent Bill Whitaker. "Above and beyond the call of duty because we had something to prove. What the military got was a ready source of young, eager, educated Americans who were eager to prove themselves."
African-Americans made up 13 percent of the total population, but comprised a full quarter of the military service.
"African-Americans have been the backbone of the ground forces of the military since World War II," Black said.
And African-Americans have gotten plenty back, too.
"The blacks in the military look at the military as a source of self-improvement and, most important, as a source of economics," Black said.
And a source of several generations of black leaders and role models -- a theme that rang through the reunion. Master Gunnery Sergeant Robert Council has three tours in Iraq under his belt. He said he would advise young black people to look at the military as a way to get on the right track.
"If you don't have no direction right now in your life, and your life is at a standstill and you don't know where you're going ... you need a foundation, and [the armed services] helps you establish that foundation," he said.
Former Staff Sergeant Bonita Williams, who served in the Marines, agrees.
"If you believe in this country, then you should be willing to go over and fight for it," she said.
But lately, the message has been falling increasingly on deaf years. African-Americans aren't signing up like they used to.
Just in the last several years, enlistment by blacks in the Army, for example, is down by about half, which means Army recruiter Sgt. Tulsa Scales has his work cut out for him. He is burning up shoe leather in the South Los Angeles area to remind African-Americans the Army can be a ticket to a bright future.
"If they say they want a career, that means we're going to talk about a career," he said. "If they say 'I want college money,' like myself, I wanted college money. That's the thing the recruiter talked to me about: college money."
The Department of Defense has studied why black enlistment has plummeted and found many of the people they call "influencers" in the black community -- parents, teachers, clergy -- feel in general that Bush administration policies have hurt African-Americans. And more than any other group, they oppose the war in Iraq.
Take 10th grader Maceo Sheffield, for example. He loves his Junior ROTC class at Los Angeles' Fairfax High School.
"I enjoy learning about respect and discipline," Maceo said. "I like the Army. I love America."
But first Maceo will have to get past his parents, Maceo Sr., and Terry Crayton, who sounds like the overwhelming majority of blacks in the Pentagon survey:
"If I was 17 or 18 years old and had that option, I would not go into the service," Sheffield said. "It's not our war."
"Exactly who are we fighting?" Crayton said. "What are we fighting for? What are we going to get out of this war?"
Other "influencers" the military pointed to include teachers, like Jamal Speakes at Los Angeles' Dorsey High. Speakes tells his students times have changed, and they don't need the military any more to get an education and a career.
"I think it is my social responsibility as a teacher, as a father, as a mentor, as person who will call themselves a role model, to give those kids the information, so they can make a well-rounded choice on what they want to do after high school," he said.
One of his students, Erica Lampkin, says she thinks she can make a difference by getting an education.
"I feel that going to college and becoming somebody, I think that's showing love to my country. Because I can change something, I can make a difference, I can change my community," she said.
"A lot of what we're seeing is, they're not falling in line with their grandfathers and uncles whose only option was the military," Speakes said.
Back in Las Vegas, some of these grandfathers and uncles who served proudly themselves worry about the ranks of black officers thinning down the road. If blacks continue to shun the military and shun the combat roles and ratings, then there won't be any future leaders -- black leaders -- in the military.
But even here, there are gung-ho Marines troubled by this war. Albert Thames retired as a staff sergeant 30 years ago.
"The war is very unpopular, and it's going to get worse," he said. "As long as it's a volunteer army, I'd tell 'em not to volunteer."
An old combat vet who loves the military, Pearl Harbor survivor Skip Davis, who spent 10 years in the Navy and 20 in the Marines, has mixed feelings.
"The 'yes' part: the money's good," he said. "And the 'no' part is going to Iraq. That's the 'no' part. I wouldn't go if I didn't have to."
And that's the attitude Army Recruiter Sergeant Scales does battle with day after day. So he hits the streets and works the phones, talking up the Army's many non-combat jobs.
"OK, what's the thing you're scared of the Army?" he said over the phone to a potential recruit. "Gotta go to war? So if you didn't have to go to war, then would you join the Army?"