Christian Jacobs, 5, of Hertford, N.C., dressed as a Marine, pauses at his father's gravestone on Memorial Day at Arlington National Cemetery in Arlington, Virginia., May 30, 2016. Christian's father Marine Sgt. Christopher James Jacobs died in a training accident in 2011.
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President Barack Obama places a wreath at the Tomb of the Unknowns to honor Memorial Day at Arlington National Cemetery in Arlington, Virginia, May 30, 2016.
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Vietnam war veterans among other guests listen to President Barack Obama at the Memorial Day observance at Arlington National Cemetery in Arlington, Virginia, May 30, 2016.
A Boy Scout salutes at the foot of a grave after volunteers placed flags at the Los Angeles National Cemetery, May 28, 2016 in preparation for Memorial Day.
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Two people look at flags representing fallen soldiers during the annual Rolling Thunder "Ride for Freedom" parade ahead of Memorial Day in Washington, D.C., May 29, 2016.
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Staff Sgt. Tim Chambers kisses his bride Lorraine Heist during the annual Rolling Thunder First Amendment Demonstration Run in Washington, D.C., May 29, 2016. Each year Chambers stands on the route at attention to salute the passing bikers, and this year he was married right before the parade.
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Visitors are reflected in the Vietnam Memorial in Washington, D.C., May 27, 2016.
Susan Walsh/AP Photo
A woman carries red roses as she walks among graves on Memorial Day at Arlington National Cemetery in Arlington, Virginia, May 30, 2016.