Americans honored service members' sacrifice for their country on Memorial Day weekend.  

Pictured: A U.S. Army soldier of the 3rd United States Infantry Regiment uses his boot to measure where to place U.S. flags on graves at Arlington National Cemetery in advance of Memorial Day in Arlington, Va., May 24, 2018.

U.S. Army soldiers of the 3rd United States Infantry Regiment arrive to place U.S. flags on graves at Arlington National Cemetery in advance of Memorial Day in Arlington, Va., May 24, 2018.

U.S. Army soldiers of the 3rd United States Infantry Regiment arrive to place U.S. flags on graves at Arlington National Cemetery in advance of Memorial Day in Arlington, Va., May 24, 2018.

U.S. Army soldiers of the 3rd United States Infantry Regiment place U.S. flags on graves at Arlington National Cemetery in advance of Memorial Day in Arlington, Va., May 24, 2018.

U.S. flags placed on graves at Arlington National Cemetery in advance of Memorial Day in Arlington, Va., May 24, 2018.

U.S. Army soldiers of the 3rd United States Infantry Regiment place U.S. flags on graves at Arlington National Cemetery in advance of Memorial Day in Arlington, Va., May 24, 2018.

A U.S. Army soldier of the 3rd United States Infantry Regiment places U.S. flags on graves at Arlington National Cemetery in advance of Memorial Day in Arlington, Va., May 24, 2018.

Flags decorate graves at Arlington National Cemetery in advance of Memorial Day in Arlington, Va., May 24, 2018.

Some of the 66 Eternal Reef balls with plaques representing each of the submarines and crewmembers lost at sea since 1900. 

The USS Kete submarine was lost as its transited to Midway Island after torpedoing three Japanese ships while on patrol in May 1942. Eighty-seven lives were lost.

People are reflected on a temporary memorial made of more than 600,000 poppies, erected at the National Mall in Washington, D.C., ahead of Memorial Day, May 25, 2018.

Gold Star mother Mona Gunn, whose son, U.S. Navy Seaman Cherone Gunn, was killed in the attack on the USS Cole in 2000, is honored by Rolling Thunder motorcyclists during a torchlit vigil at the Vietnam Veterans Memorial on the National Mall in Washington, D.C., May 25, 2018. 

Rolling Thunder motorcyclists, who ride annually on Memorial Day in support of U.S. military veterans, stand in prayer before having their bikes blessed during a brief service at the National Cathedral in Washington, D.C., May 25, 2018.

The U.S. Nancy Blue Angels perform as part of a Memorial Day event, the Bethpage Air Show, on Long Island, New York, May 26, 2018.

Local residents take part in the Memorial Day Parade in Bandera, Texas, May 26, 2018. 

An "America the Beautiful" sign hangs from the tail of a horse during the Memorial Day Parade in Bandera, Texas, May 26, 2018. 

Two men visit the Vietnam Memorial as thousands of military veterans and their supporters participate in the 31st annual Rolling Thunder motorcycle rally and Memorial Day weekend "Ride for Freedom" motorcycle procession in Washington, D.C., May 27, 2018.

A participant of Rolling Thunder walks near the Vietnam Memorial in Washington, D.C., May 27, 2018.

A woman waves at riders as thousands of military veterans and their supporters participate in the 31st annual Rolling Thunder motorcycle rally and Memorial Day weekend "Ride for Freedom" motorcycle procession in Washington, D.C., May 27, 2018.

A man salutes as riders participate in the 31st annual Rolling Thunder motorcycle rally and Memorial Day weekend "Ride for Freedom" motorcycle procession in Washington, D.C., May 27, 2018.

Riders participate in the 31st annual Rolling Thunder motorcycle rally and Memorial Day weekend "Ride for Freedom" motorcycle procession on Constitution Avenue in Washington, D.C., May 27, 2018.

A man pays tribute on Arlington Bridge, as thousands of military veterans and their supporters participate in the 31st annual Rolling Thunder motorcycle rally and Memorial Day weekend "Ride for Freedom" motorcycle procession in Washington, D.C., May 27, 2018.

Participants gather in the parking lot of the Pentagon as thousands of military veterans and their supporters participate in the 31st annual Rolling Thunder motorcycle rally and Memorial Day weekend "Ride for Freedom" motorcycle procession in Washington, D.C., May 27, 2018.

A Memorial Day Observance is held at the National World War II Memorial, paying tribute to the more than 400,000 servicemen and women who lost their lives during the war, in Washington, D.C., May 28, 2018.

Participants gather for a Memorial Day Observance at the National World War II Memorial, in Washington, D.C., May 28, 2018.

World War II veteran Bernard Friesland is presented with a wreath during a special Memorial Day Observance at the National World War II Memorial, in Washington, D.C., May 28, 2018.