WASHINGTON — The last US veteran of World War I, who lied about his age to join the army in 1917, has died, ending America's living connection with the Great War. He was 110.

The indomitable Frank Buckles, who also survived three years in a Japanese prisoner of war camp, "died peacefully" of natural causes early Sunday at his home in Charles Town, West Virginia, a family spokesman said.

Buckles celebrated his 110th birthday on February 1, but his family said his health had been failing since late last year.

He spent the last years of his life campaigning for a national WWI memorial in Washington, testifying before a Senate panel in December 2009 on the matter.

Buckles "actively pursued his role as the torchbearer for his fellow soldiers from the 'Great War,'" the spokesman David DeJonge said.

Born Frank Woodruff Buckles in Missouri in 1901, Buckles rushed to enlist when the United States entered the war in April 1917 after reading about the conflict in the newspapers.

The marines and the navy turned him down because he was only 16, but Buckles managed to convince the army recruiter he was 21.

Some 4.7 million Americans fought in World War I, the vast majority in the American Expeditionary Force that sailed to Europe.

When the Americans entered the war, begun in 1914, Russia was on the verge of collapse, thousands had been slaughtered in the trenches on the western front, mutinies were breaking out in the French army and German submarines were taking a heavy toll on allied shipping. By the time the shooting ended on November 11, 1918, some 8.5 million people had died.

From the start, Buckles was itching to get to the front. "A knowledgeable old sergeant said if you want to get to France right away, go into the ambulance corps," he said in a 2001 interview with the Library of Congress.

Sailing to Europe in December 1917 aboard the ship that five years earlier picked up the survivors of the Titanic, Buckles landed in Britain.

"During my stay in England, I drove a motorcycle sidecar, then Ford ambulances and cars. Perseverance paid off and I got assigned to follow an officer who had been left behind from his unit and I got to France," he said.

But Buckles, who rose to the rank of corporal, never made it to the front lines and after the war, his unit escorted prisoners back to Germany.

By the time he left the army in 1920, there was wide disillusionment back home and a feeling that perhaps the United States had been tricked into the war.

"It led to a tremendous distrust of Europe that lasted a generation, and a desire to use the Atlantic as a gigantic moat to keep European problems out," said University of California at Berkeley historian Richard Candida Smith.

US veterans of the Great War got mixed treatment at home. Dead soldiers were honored, but there was little help for the survivors.

Buckles said the only benefit he received for his service was free membership at the YMCA health club.

He entered the shipping industry after the war and in 1941 traveled to the Philippines to represent a US shipping company.

Belatedly on the front line, Buckles was captured by invading Japanese soldiers when they captured Manila in January 1942, just weeks after the attack on Pearl Harbor brought the United States into World War II.

He was to spend the next three years in a prison camp.

After the war, Buckles returned to the United States, married and bought a cattle farm in West Virginia.

"Nobody here knew that I had been in World War I until quite recently," he told the Library of Congress.

That was until French president Jacques Chirac awarded him the Legion of Honor (Legion d'honneur) medal at in 1999.

In March 2008, Buckles was honored at a special ceremony at the Pentagon and the White House by president George W. Bush.

His wife Audrey died in 1999 and he is survived by his daughter Susannah, who still runs the Virginia farm with her husband.