The Tomb of the Unknown Soldier marked its 100th anniversary Nov. 11 with a full honors procession that replicated the journey made in 1921 when the unknown soldier from World War I was brought to his final resting place at Arlington National Cemetery.

Members of the public were allowed to line the special route inside the cemetery in Virginia as a joint service flyover soared overhead. Later in the day, which also was Veterans Day, President Joe Biden led a wreath-laying ceremony at the tomb.

“One hundred years ago today, an American soldier from the first World War, as the tomb says, ‘Known but to God,’ completed the voyage from an unidentified battlefield in France, over the rough Atlantic seas, here to Arlington National Cemetery,” Biden said.

Today, the tomb is “one of the most hallowed American monuments,” and it represents “the generations of Americans who dared all, gave all, risked all,” Biden said.

Veterans are the “soul of America,” Biden said. “For us to keep faith with American veterans, we must never forget exactly what was given us, what each of them was willing to put on the line for us.”

America has many obligations, Biden said, but it has “one truly sacred obligation, to properly prepare those and equip those who we send into harm’s way and care for them and their families while they’re both deployed and when they come home.”

He added, “This is a lifetime, sacred commitment. It never expires. We’ve asked so much of you for so long, and our nation is grateful.”

The procession and wreath-laying on Nov. 11 marked the culmination of a series of events commemorating the tomb’s centennial.

Other events included a flower ceremony Nov. 9–10 that, for the first time in nearly a century, allowed members of the public to walk on the Tomb of the Unknown Soldier Plaza and lay flowers at the sacred site. There also was a 21-gun salute Nov. 9 and several local commemorations across the country led by a group of nonprofit organizations dedicated to those who served as tomb guards.

On March 4, 1921, Congress approved the burial of an unidentified American soldier from World War I in the plaza of Arlington National Cemetery, according to the cemetery’s website. Sgt. Edward Younger, a World War I veteran who was wounded in combat, chose the unknown soldier from among four identical caskets.

Additional unknowns were added in 1958 and 1984, and the tomb has since come to symbolize the sacrifices of all U.S. service members.

The Army has maintained a 24-hour guard over the tomb since July 2, 1937. Sentinels from The Old Guard assumed those duties on April 6, 1948, and they have maintained a constant vigil ever since.

“As our troops continue to stand watch over this hallowed ground through the next 100 years and beyond, may we always honor and remember those who gave so much to our grateful nation,” said Maj. Gen. Allan Pepin, commander of Joint Task Force-National Capital Region and the U.S. Army Military District of Washington.

For more information about the Tomb of the Unknown Soldier and centennial, click here.