LOS ANGELES -- Frank Woodruff Buckles, a one-time Missouri farm boy who was the last known living American veteran of World War I, has died. He was 110.

Buckles, who later spent more than three years in a Japanese POW camp as a civilian in the Philippines during World War II, died Sunday of natural causes at his home in Charles Town, W.Va., family spokesman David DeJonge said.

A total of 4,734,991 Americans served in the military during World War I.

When 108-year-old Harry Landis died Feb. 4, 2008, in Sun City Center, Fla., Buckles became the war's last standing U.S. veteran.

"I always knew I'd be one of the last because I was one of the youngest when I joined," Buckles, then 107, told the New York Daily News. "But I never thought I'd be the last one."

Earning that distinction resulted in numerous honors for Buckles in 2008.

In March 2008, he met with President George W. Bush at the White House, then attended the unveiling of an exhibit at the Pentagon of recent photographic portraits of nine World War I veterans, including himself, who had lived to age 100 or older.

In April, then-West Virginia Gov. Joe Manchin formally dedicated a section of the new, four-lane state Route 9 in honor of Buckles, who lived with his daughter, Susannah Flanagan, and her husband on a cattle farm near Charles Town, a small community in West Virginia's eastern panhandle.

And on Nov. 11 -- the 90th anniversary of the signing of the armistice -- Buckles was recognized by the secretary of the Department of Veterans Affairs as "our last living link" to World War I.

He was born Feb. 1, 1901, on a farm near Bethany, Mo., and moved with his family to a farm in Oklahoma as a teenager.

When the United States entered the war in April 1917, Buckles was eager to enlist -- even though he was only 16.

After being rejected by Marine and Navy recruiters, Buckles tried the Army. When the recruiter asked to see his birth certificate, Buckles said Missouri didn't keep birth records when he was born and the only record was what was written in the family Bible.

His word was good enough for the Army.

Buckles enlisted on Aug. 14, 1917, and went through basic training at Fort Riley, Kan.

In his Daily News interview, Buckles recalled that an old sergeant told him, "If you want to get to France in a hurry, then join the ambulance service."

He shipped off to England in December 1917 on the RMS Carpathia, the ocean liner that had rescued survivors of the Titanic in 1912.

Initially stationed in England, where he drove dignitaries around, he successfully hounded his officers for an assignment in France. He never got close to the action. But, as he told columnist George F. Will in 2008, "I saw the results."

When the war ended, Buckles helped escort prisoners of war back to Germany.

After returning home a corporal, he attended a business school in Oklahoma City for several months and, among other jobs, worked for a bank. But he grew bored.

Satisfying a desire for adventure, he got a job with the White Star Line shipping company and traveled the world. He was in Manila when the Japanese attacked the Philippines on Dec. 8, 1941, and was among the Western civilians later taken prisoner.

After returning home, Buckles married Audrey Mayo, whom he had met in California before the war. In 1954, they moved to the 330-acre West Virginia cattle farm.

Buckles' wife died in 1999, the same year French President Jacques Chirac awarded him the French Legion of Honor.

Buckles continued to live on his farm and reportedly drove a car and a farm tractor until he was 102.