Shortly after Army Lt. Jack H. Jacobs was awarded his Medal of Honor in 1969, he sat down with some other recipients at a reunion table.

There were more than 400 of them alive at the time, including fighter pilot greats Eddie Rickenbacker from World War I and Pappy Boyington from World War II.

There was even a survivor of the Chinese Boxer Rebellion in 1900.

Today, some 40 years later, there are 87 Medal of Honor men left, with an average age of 78. If male longevity statistics hold, nearly all from this group will be gone in the next dozen or so years.

The dwindling ranks mean Americans need to recognize the sacrifices of those who came before them, Jacobs said Thursday, adding that even if you're not in uniform, find a way to do something for your country.

"Pay attention to your responsibility as a citizen of the United States," he told several hundred members of The Citadel's Class of 2013.

Medal of Honor recipients began fanning out into the Charleston community Thursday as part of their annual convention, including taking part in a massive autograph session where about 48 of the 52 men in town for the gathering spent several hours aboard the aircraft carrier Yorktown at Patriots Point, signing everything from books to collector cards to military-issue helmets.

Civilian Robert Wessinger of Chapin said he thinks he got signatures from all but one of the recipients who appeared for the signing.

"It's something we all hope we could do if we we're in their shoes," he said of the bravery and individual deeds on display.

Two of the medal-wearers said they didn't mind being treated like rock stars to autograph seekers.

"I'm in awe of it," said George Wetzel, 63, of Milwaukee, an Army helicopter door-gunner who was awarded his medal for his service during a ground fight in Vietnam in which he lost his left arm.

Army Cpl. Rudy Hernandez of Fayetteville, N.C., took part in the signing too, but had to use a rubber stamp to punch his signature onto cards and books.

Hernandez, 79, earned his medal from action in Korea when he rushed the enemy armed only with a rifle and bayonet "before falling unconscious from grenade, bayonet, and bullet wounds," his citation reads.

Jacobs was awarded his medal from action in Kien Phong Province, South Vietnam, on March, 9 1968. He was an adviser to South Vietnamese troops who made repeated trips under fire to evacuate wounded and their weapons, saving the lives of a U.S. adviser and 13 other soldiers in the process.

In his address to the cadets, Jacobs, 65, said he was perpetually scared in combat and isn't afraid to be honest about it today. "Anybody who says he was in combat and said he was not scared is a lying dog," he told the cadets, adding, "If I wasn't in combat, I was scared I was going to be in combat."

One cadet asked Jacobs a question he'd never heard before: What does it feel like when he first puts on his medal?

Like most medal wearers, Jacobs spoke of pride and privilege, then answered that each member of the group is "not wearing it for himself. He's wearing it for somebody who can't."

The Medal of Honor Society convention continues through Saturday.