Memorial Day 2011 is a United States federal holiday observed on the last Monday of May (May 30 in 2011). Formerly known as Decoration Day, it commemorates U.S. soldiers who died while in the military service. First enacted to honor Union soldiers of the American Civil War. It was extended after World War I to honor Americans who have died in all wars.
Memorial Day often marks the start of the summer vacation season, and Labor Day its end.
via Memorial Day 2011.