href="http://en.wikipedia.org/wiki/Memorial_Day">From Wikipedia

Memorial Day is a United States

federal holiday observed on the last Monday of May (May 31 in 2010). Formerly

known as Decoration Day, it commemorates U.S. men and women who died while in

the military service.  First enacted to honor Union  soldiers of the

American Civil War (it is celebrated near the day of reunification after the

Civil War), it was expanded after World War I.

Many people observe this holiday by

visiting cemeteries  and memorials. A national moment of remembrance takes

place at 3 p.m. local time. Another tradition is to fly the flag of the United

States at half-staff  from dawn until noon local time. Volunteers often

place American flags on each grave site at National Cemeteries.