He says, "I know that I am a representative of all those who have gone before me. Those veterans, especially those who made the supreme sacrifice, should be remembered."

Actually, there is already a relatively small monument in the nation's capital, recognizing the 500 or so District of Columbia residents who died in World War I. It was dedicated in 1931, when Americans typically honored their war dead locally, town by town. That changed in 1982 when the National Vietnam Veterans Memorial was unveiled on the Mall, followed by national memorials to veterans of World War II and the Korean War.

Historically, every war commemorated on the Mall can trace its roots back to World War I. More Americans died in that war than in Korea and Vietnam combined. The U.S. played a significant role in winning the war for the Allies and, in the process, was transformed into a world power.

So why no national memorial? One obstacle has been the territorial feud between those who want to enhance the existing D.C. monument and those who have insisted that the recently restored Liberty Memorial in Kansas City, Mo., the site of the National WWI Museum, already is the national memorial. Both sides have had strong supporters in Congress.

The District's monument has deteriorated badly over the decades -- so badly that in 2006 the D.C. Preservation League put it on its Most Endangered Places list. This led Edwin L. Fountain, then the League's president, to establish the World War I Memorial Foundation along with David DeJonge, a photographer. Its objective: to restore, expand, and re-dedicate the existing monument as a "National and District of Columbia World War I Memorial." Frank Buckles joined that effort, too.

"When I saw the sad state of repair that the D.C. memorial was in, I felt that something should be done about it," Buckles said after DeJonge took him to see it in 2008.

But for two years nothing could proceed because the two groups could not reach an accord. Earlier this month, however, the foundation and the museum tentatively agreed on a compromise bill whereby both sites would be designated national World War I memorials. Now the final battle remains -- to push that bill through Congress. 

Advocates hope a memorial will reverse our national tendency to overlook the 4.7 million Americans who served in the First World War. In 2003, when I set out to find a few living U.S. veterans of that war, no one, from the Department of Veterans Affairs on down, seemed to have any idea how many might be left, much less where they were. I eventually found more than 30. They included men like Laurence Moffitt, a corporal in the 26th Division who spent his 21st birthday hunkering down in a rotten trench; Bill Lake, a machine gunner whose good friend was killed by a German sniper as they were chatting; Anthony Pierro, an Italian immigrant who survived three fierce battles; and George Briant, a Cajun artilleryman who saw many of the  men in his battery killed on the very last night of the war.

The American Battle Monuments Commission, established by Congress in 1923 and led by John J. Pershing, former commander of the American Expeditionary Force in France, built many beautiful monuments to World War I -- but they're all in Europe. The commission's charge was to create these monuments -- and national cemeteries -- at sites of American heroism so they might not be forgotten.  But few Americans visit those sites anymore. Few even know they're there.

The veterans I interviewed had one thing in common: No matter what they thought about their war or war in general or Army life, they were proud of their service to their country. And Frank Buckles is proud to stand up for them now. "Veterans of all the wars deserve their honor," he says.

Richard Rubin is writing a book about the last American veterans of World War I