As America marks Veterans Day on Monday, Ancestry is opening its Fold3 archive free of charge. This makes more than 350 million military records from both World Wars available through midnight. It’s an opportunity for black-and-white photographs in family albums to speak, and to flesh out war stories that veterans often don’t discuss.

“Traditionally,” according to Fold3.com, “the third fold in some flag-folding ceremonies honors and remembers veterans for their sacrifice in defending their country and promoting peace in the world.” Through research, those contributions can be expanded with a picture, rank, theater of service, or newspaper clippings.

“Old soldiers never die,” General Douglas MacArthur said in his 1951 farewell address, “they simply fade away.” It’s an apt metaphor for the regret many feel after loved ones are gone, taking their personal history with them. We may wish we’d asked a grandfather if he enlisted after Pearl Harbor or was drafted. We might know that a grandmother served in the Women’s Army Corps and nothing more.

Archives like Fold3, which describes itself as “the web’s premier collection of original military records,” gives descendants a chance to find elusive answers. They can break out of dead-ends in genealogical research and help ancestors speak. It’s worth a look even if you checked years ago and believe there’s nothing to be found.

Popular collections at Fold3 include Marine Corps Muster Rolls, dating from 1798 to 1958, Missing Air Crew Reports from the World War II era, and Army Air Force photos. Punching in my last name turned up my great uncle, James Karayanis, and his 1942 registration for the so-called “Old Man’s Draft.” The fourth Selective Service registration, it included those aged 45 to 64, too old for combat.

That draft card is a new discovery for me, filling in the portrait of a man I never met. Unlike other forms of research, a family tree is never completed. They grow over time thanks to armies working to digitize records. So, clues available this Veteran’s Day might not have been offered on the previous 11th hour of the 11th day of the 11th month — when World War I ended in 1918.

To demonstrate the stories waiting to be uncovered, an author at the Fold3 blog, Jenny Ashcraft, posted a 1944 record from Germany “with torn and burned edges” that mentioned American POWs. Curious, she focused on Sergeant Curtis E. Finley “to share the tips and strategies we used and demonstrate how you can recreate the military story of your ancestors.”

Google translate produced an English version of the document, which recorded that Finley’s B-17 Flying Fortress was shot down behind enemy lines on January 29, 1944. He’d evaded the Germans occupying France and walked from Paris south. His luck ran out at the Spanish border, where he was captured. Among his belongings, he carried a fake ID and a pocket knife.

With these clues, Ms. Ashcraft headed to Newspapers.com, which has over a million pages — including archives of the Sun from 1859 to 1920 — to flesh out Finlay’s journey. His B-17 bomber had taken off from a Royal Air Force station at Molesworth, England, intending to drop its load over Frankfurt, Germany. But the Flying Fortress encountered engine trouble, lost altitude, and was shot out of the sky.

Finley survived the crash and contacted the French Resistance. A local family hid the engineer and top turret gunner in their attic for several months before supplying him with the forged documents the Germans found in his pocket. The British liberated Stalag-Luft IV prison camp at the end of the war, ending Finlay’s 15 months in captivity.

“We searched ‘Stalag-Luft IV’ on Fold3,” Ms. Ashcraft wrote, “and found numerous Memorials where POWs described conditions at this notorious prison camp. Their statements give context to what Finley must have experienced.” After recovering back home in Nebraska, Finlay reenlisted in 1946 and served for another 20 years.

In 1949, Finley returned to Paris and reunited with the family that had hidden him from the Nazis. That nugget was reported in his obituary, printed by the Spokane Chronicle when he passed away in 1980. Finley’s story might have been forgotten, buried in filing cabinets and basements around the world. Now, he can be remembered.

Only when veterans are gone do we realize it’s too late to fill in the blanks in their life stories. But thanks to archives like Fold3, we can find more information than ever. It’s a chance to remember the sacrifices previous generations made to defend liberty and promote peace, and to ensure that while the old soldiers in our family may fade away, their stories never die.