Mark Levitch, who has set out to build an online database of every World War I memorial in the U.S., poses at the the District of Columbia War Memorial. (Astrid Riecken/ The Washington Post)

On Nov. 14, 1921, President Warren G. Harding and Army Gen. John J. Pershing set the cornerstone for Washington’s colossal National Victory Memorial, at Sixth Street and what is now Constitution Avenue.

World War I had just ended, and this huge edifice was planned, in part, to honor the sacrifice of Americans in “the Great War.” There were to be stars representing each of the nation’s war dead on the ceiling and an 11,000-seat auditorium inside.

But after the foundation and a long set of stone steps were built, the project stalled. Money dried up. The war faded from memory. And the enterprise was scrapped.

With this year’s start of the centennial of World War I (1914-1918), Mark Levitch, a Washington art historian, has been scouring the country for memorials to the war that was to end all wars.

He has searched the Internet and taken to the road in hopes of assembling, with the help of the public, a database of the war’s forgotten monuments. He calls it the World War I Memorial Inventory Project.

Mark Levitch estimates that there may be 10,000 World War I memorials in the United States. (Astrid Riecken/ The Washington Post)

He has found about 2,000 so far, including one mass-produced statue that was sold by a savvy sculptor at least 140 times to small towns across the country.

Some memorials have been damaged, vandalized or stolen. Others have been torn down or are crumbling from neglect. Others remain moving tributes to the men and women who went off to the war.

Levitch estimates that there may be 10,000 World War I memorials in the United States.

He’s also found records of monuments that came and went — fabulous but temporary victory arches in New York and in Washington, the latter a block from the White House.

And he has learned of a few, like the giant victory building, that never got off the ground.

“In our country, we give most attention to World War II and the Civil War,” he said in a recent interview. “World War I is very much overlooked.”

Americans came late to the conflict. And even though the sprawling Meuse-Argonne Offensive in 1918 was probably the largest and bloodiest battle in American history, killing more than 25,000 Americans, scholars say it is barely remembered today.

The Civil War’s Battle of Gettysburg, which claimed about 7,000 lives from both sides, and World War II’s Battle of the Bulge, which killed about 19,000 Americans, are much more famous.

But at the time, World War I “was remembered . . . as a momentous occasion for the United States,” Levitch said. “It represented the ushering in of the American century . . . [and] it made the U.S. a world power.”

An estimated 5 million Americans served, and more than 100,000 died, many of them in the trenches and shell holes of France.

The United States didn’t join its allies, primarily Britain, France and Russia, in the struggle against Germany and Austria-Hungary until April 1917. But large U.S. forces arrived at a crucial moment and played a major role in the victory.

Levitch, who lives in Dupont Circle, is an author and student of World War I who works as a contract writer at the National Gallery of Art.

He said that although the nation’s monuments to World War I often go unnoticed, “they’re everywhere.”

“Many of them are very modest, simple honor rolls. And some of them are grandiose, by the greatest architects and sculptors of the day,” he said.

The recently restored D.C. War Memorial was created in part by architect Nathan C. Wyeth, who designed the Oval Office in the White House.

The gilded figure atop the towering 1st Division Monument, south of the Eisenhower Executive Office Building, was sculpted by Daniel Chester French, who also worked on the Lincoln Memorial.

And then there was E.M. “Dick” Viquesney.

The little-known Indiana sculptor and monument salesman created the plain metal statue of a charging soldier called the “Spirit of the American Doughboy” that today exists in towns all over the country.

The statue was mass-produced in the years after the war and marketed to communities that did not have money for a huge monument, Levitch said.

Viquesney sent out brochures promoting his statue and providing a nine-point fundraising plan, complete with testimonials. “No community is too small or too poor to have its own doughboy memorial,” his sales pitch went.

As a result, his “doughboys” exist in 39 states, according to a Web site, the E.M. Viquesney Doughboy Database.

Maryland has one in Emmitsburg and another in Crisfield. Virginia has one in Petersburg.

Ohio has 12, the most of any state. Nebraska used to have one in Omaha, but vandals took its left hand in 1941, and the statue vanished in 1974, according to a Smithsonian inventory of American sculpture.

Levitch said he got the idea to catalogue World War I monuments in 2009 when he was unable to track down one that the French were said to have given the United States. It was supposed to be in Arlington National Cemetery.

His survey does not include tombs, such as that of the Unknowns in Arlington or the beautiful National Cathedral tomb of the aviator Norman Prince. “It’s a tricky distinction,” he wrote in an e-mail. “Otherwise it would be hard to exclude the tombstones of US WWI fatalities from the inventory.”

Washington has a forest of Civil War monuments, but there are also such World War I tributes as a haunting statue outside the Red Cross building honoring nurse Jane A. Delano and the 296 nurses who died during the war.

The Agriculture Department Building on the Mall has a marble relief sculpture saluting department employees who died in the war.

Arlington Cemetery has, among other sites, a monument to 23 chaplains who lost their lives in the war and another to fallen Americans who fought in the Canadian army.

Elsewhere, New York’s old Polo Grounds sports stadium had a plaque honoring a former baseball player, Eddie Grant, who joined the Army and was killed in battle in 1918.

Kansas City, Mo., has the soaring Liberty Memorial, home of the National World War I Museum. It’s the most impressive such memorial in the country, Levitch said.

And tiny Kimball, W.Va., has the elegant Kimball World War I Memorial, a building dedicated to the service of African Americans.

“Every one has a story,” Levitch said. “And they’re often great. There are narratives everywhere.”

Take Washington’s aborted victory building, “a good and virtually unknown story,” Levitch said.

It was originally proposed as a memorial to George Washington. But when World War I came, supporters figured they’d make faster progress if they called it a war memorial, too, Levitch said.

“It is fitting . . . that we should lay the cornerstone of this great building where, in years to come, our people may gather with peaceful purpose,” Pershing, who had led U.S. forces in the war, said at the cornerstone ceremony.

But the project was huge and expensive. The site sat empty for over a decade. Eventually, the foundation was removed to make way for the National Galley of Art.

By then it was 1937, two years shy of the start of the next world war.