They came to honor those who fought and those who fell in Southeast Asia.
More than 58,000 Americans died in Vietnam.
Former Marine Michael Grigsby of Boise got two Purple Hearts there.
"A grenade ended up coming over, got me in the arm," he said.
"Number two was, well they call them IEDs now. It was dynamite wrapped with shrapnel."
Vietnam, of course, was a very divisive war in our country's history. And in one of America's most shameful episodes, returning Vietnam vets got little respect from the public.
"We served our country honorably and the people got us confused with the political dissent that was going on," said Henry Parker who served in Vietnam with the United States Army.
But Parker thinks America has made up for the way it treated returned Vietnam vets.
"I think it has," he said. "Ceremonies like today's are helpful. There's still some that have been hurt terribly by it."
It's hard to undo that hurt but America has never disrespected its proud warriors in such a way since.
One more lesson learned from Vietnam