Foreboding, 11-foot-tall iron gates guard the entrance and a narrow path takes you between jagged rocks. A few paces later, you step into a room and a voice commands "Halt!" You find yourself facing dozens of pistols and rifles, some with bayonets.

And there, in the new National Prisoner of War Museum, American POWs from the Revolution to the Persian Gulf War explain in their own words, writing and artifacts what it was like to be held by the enemy, often in inhumane conditions, almost always without knowing whether they would ever be freed."Some of the most terrible and difficult sacrifices undergone by fighting men and women have been as POWs," said Sen. John McCain, who spent more than five years captive in Hanoi after being shot down in Vietnam. "We should always be reminded of their service."

On April 9, the Arizona Republican will help dedicate this newest national museum, honoring the estimated 800,000 Americans who have been held as POWs. The dedication, on the anniversary of the beginning of the brutal Bataan Death March of U.S. prisoners captured by the Japanese in World War II, likely will draw many of the estimated 56,000 surviving ex-POWs.

"We've waited a long time for this," said 69-year-old Bill Fornes, a POW in the Korean War who lives in Valdosta, Ga.

Andersonville is the site of the infamous Confederate prison camp where Americans held Americans in harsh, disease-ridden conditions during the Civil War. Nearly 13,000 Union soldiers died at Andersonville, more than a fourth of those who were held here.

Union veterans groups and then the Army helped preserve much of the prison site and the cemetery for some 12,000 soldiers who were buried side-by-side in trenches.

Andersonville drew renewed national interest during the Civil War Centennial of the 1960s. The Vietnam War with its POWs led to congressional support for making Andersonville a national historic site, and in the 1980s the American Ex-POWs organization began pushing for a museum.

Money for the $5.8 million project was raised by a congressionally-authorized sale of commemorative POW coins, private donations, federal funds and contributions by the state of Georgia.

Andersonville still arouses bitter feelings for some, but it is the best available place for such a memorial, said Fred Boyles, National Park Service superintendent for the site. It's about a three-hour drive from Atlanta, and 22 miles from the Jimmy Carter National Historic Site at Plains.

"We can't take people to the Hanoi Hilton," or to German stalags or to the prison ship used by the British to hold Americans, Boyles said. "We can bring them to Andersonville, and show them what POWs went through throughout all history."

Northern outrage over Andersonville, called Camp Sumter during the war, led to the hanging of its commander, Confederate Capt. Henry Wirz. Confederate heritage buffs say the history written by Union victors usually neglects to point out that Confederate prisoners also were held in severe conditions.