Memorial Day is a United States federal holiday observed on the last Monday of May (May 31, 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.
Following the end of the Civil War, many communities set aside a day to mark the end of the war or as a memorial to those who had died. Some of the places creating an early memorial day include Sharpsburg, Maryland, located near Antietam Battlefield; Charleston, South Carolina; Boalsburg, Pennsylvania; Petersburg, Virginia; Carbondale, Illinois; Columbus, Mississippi; many communities in Vermont; and some two dozen other cities and towns. These observances coalesced around Decoration Day, honoring the Union dead, and the several Confederate Memorial Days.