John R. McNeill is a professor of history at Georgetown University and a vice president of the American Historical Association.

My 94-year-old father and two of my uncles were among the 16.5 million men and women who served in the American armed forces during World War II. Both uncles, and another who served with the Canadian military in the war, are now dead. I have only snippets of information about their lives in uniform. At my urging, my father recently wrote the story of his life on active duty in the U.S. Army from 1940 to 1946....

Those stories are a form of national treasure. For years, historians, journalists and family members have been collecting letters, diaries, journals and interviews from a few of those 16.5 million. The Veterans History Project at the Library of Congress, created by an act of Congress in 2000, has materials of some sort from 48,000 World War II vets. University libraries, state historical societies, military units and other organizations have collected a few thousand more. No one knows exactly how many because there is no clearinghouse or coordination. But it is likely that fewer than 1 in 200 of these veterans’ stories are preserved in any fashion.

Of those that are preserved, a small share is digitized and easily accessible to the public. The Veterans History Project has put up 7,000 World War II vets’ stories on its Web site. The Rutgers Oral History Archives have an additional 469. The total in all digitized collections is well under 10,000. For the rest, one has to travel to a library or historical society....