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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. soldiers who died while in the military service.^[1] 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 extended after World War I to honor Americans who have died in all wars.

In the United States, Memorial Day marks the unofficial (i.e. non-astronomical) start of summer, just as Labor Day marks the unofficial end of the season.

Begun as a ritual of remembrance and reconciliation after the Civil War, by the early 20th century, Memorial Day was an occasion for more general expressions of memory, as ordinary people visited the graves of their deceased relatives, whether they had served in the military or not. It also became a day increasingly devoted to shopping, family get-togethers, trips to the beach, and national media events such as the Indianapolis 500 auto race, held since 1911 on Memorial Day^[2].