Memorial Day, formerly known as Decoration Day, is a U.S. holiday that takes place on the last Monday in May. The Day honors those who have died in the nation’s wars. It originated during the American Civil War when citizens placed flowers on the graves of those who had been killed in battle. More than a half dozen places have claimed to be the birthplace of the holiday, including: Boalsburg, Pennsylvania; Charleston, South Carolina; and Columbus, Mississippi. However, by congressional proclamation in 1966, Waterloo, New York, was cited as the birthplace, in 1866, of the observance.