The old soldiers stood ramrod straight, some with the help of canes, as a Marine Corps band played the national anthem at the dedication of the National Prisoner of War Museum here Thursday. Try as they might, some could not keep their saluting hands from quivering with palsy.

For others, it was the poignancy of the day and not the infirmities of age that made them tremble. After all this time, after the years of torture and deprivation and the decades of haunting memories, two senators and a governor and more than 3,000 others had come to pay tribute to the singular sacrifices they made for American liberty."Now people will know what we've done," said Bill J. Ashworth, a Korean War veteran in a wheelchair, who began wiping away tears as he recalled his 33 months of captivity at the hands of the Chinese. "They'll know the price we paid for our freedom."

The mission of the new museum here, built on the site of a Civil War prison in southwest Georgia, is to ensure that Americans never forget the 800,000 soldiers taken prisoner in their country's wars, from the revolution of 1776 to the Persian Gulf War of 1991.

Prisoners of war have long had their own organizations dedicated to preserving the memories and the camaraderie of their torment. But many have felt that their government and their fellow citizens never adequately acknowledged their contributions.

That is particularly true of those taken captive in World War II, men who came home with the rest of the troops to a jubilant country that never paused to recognize that some soldiers had been severely scarred by their detention. Many stoically kept their nightmares to themselves. But as their generation began to die out, a new urgency emerged.

"To a large extent, we, as prisoners, didn't talk about it," said John S. Edwards, a veteran of three wars who was taken prisoner after his plane was shot down over Germany in World War II. "We returned to our communities, be-came leaders of our communities. Now, if I may use a euphemism, we want to capture those stories. This museum tells the whole story of those who truly know what it's like to be without freedom."

The 10,000-square foot museum stresses the commonality of prisoners' experiences in various conflicts rather than depicting the uniqueness of captivity in individual wars. There are sections on capture, on living conditions, on communications, on privation, on morale and relationships, and on escape and freedom.

Throughout Thursday's dedication ceremonies, which were held under an expansive white tent, speakers referred repeatedly to the common struggle waged by prisoners of war to preserve their dignity and humanity.

"Their story is the story of a struggle against daunting odds to choose their own way, to stay faithful to a shared cause, to remain human beings in a world where they were treated like animals," said Sen. John McCain of Arizona, a Navy pilot who was shot down over Hanoi in 1967 and spent more than five years in prison in North Vietnam. "Their humanity, so ironic and gallant in its opposition to organized inhumanity, was their glory."

Most of the $5.8 million cost of the museum was raised by private veterans groups.