President Obama is heading to Arlington National Cemetery on Monday to mark Memorial Day. Obama said the annual holiday honoring America's war dead was especially meaningful this year because it is "the first Memorial Day since our war ended in Afghanistan." The U.S. still has about 9,800 troops expected to remain in Afghanistan until next year, though. Observances began a day early on Sunday, when thousands of motorcycle riders participated in the annual Rolling Thunder rally in Washington, D.C., to draw attention to prisoners of war and soldiers missing in action.