US Marks Memorial Day to Honor War Dead

President Barack Obama speaks at the Memorial Day Observance at the Memorial Amphitheater at Arlington National Cemetery, May 28, 2012.

President Obama lowers his head during a wreath-laying cermony at the Tomb of the Unknowns in Arlington National Cemetery in Arlington, Virginia, May 28, 2012.

General John Allen, the top U.S. commander in Afghanistan, salutes before he observes Memorial Day at ISAF headquarters in Kabul, Afghanistan, May 28, 2012.

A member of the U.S. Army Old Guard pays his respects at the grave of U.S. Army Major Douglas Sloan, before placing a flag at one of the over 220,000 graves of fallen U.S. military service members buried at Arlington National Cemetery.

People visit the Vietnam Veterans Memorial, etched with the names of more than 58,000 U.S. servicemen and women who died in the war, on Memorial Day weekend in Washington, May 27, 2012.

Cathy Ridge touches an American flag at the grave of her husband, retired U.S. Marine Gunnery Sgt. Charles Edward Ridge, May 28, 2012, at the Georgia National Cemetery in Canton.

Visitors stop at the Korean War Veterans Memorial ahead of Memorial Day in Washington, May 27, 2012.

With Arlington National Cemetery as their backdrop, motorcycle riders take part in the 25th annual Rolling Thunder First Amendment Demonstration Run in Washington, May 27, 2012.

A Marine salutes as motorcycles drive past during the annual Rolling Thunder parade ahead of Memorial Day in Washington, May 27, 2012.

World War II veteran Jesse R. Turner salutes while being comforted by Helen Marie Misel at a display of more than 1700 United States flags in Shawnee, Kan., May 26, 2012.