After the Civil War ended in 1865, many communities both north and south began holding memorial days honoring those who died. Yale University professor of history David Blight holds that the first commemoration was held at the race track in Charleston, South Carolina by liberated slaves in 1865. Purportedly, the freed slaves unearthed a mass grave for Union soldiers who died in captivity at a prison camp nearby, and re-buried the soldiers in individual graves and declared these a Union graveyard. In 1868 the freed slaves returned on May 30th to decorate the graves with flowers, creating the first "Decoration Day." A parade and picnic were held to commemorate the dead.
General John Logan, commander of the Grand Army of the Republic, officially proclaimed May 30 as Memorial Day in 1868. The holiday was recognized by all states who had been members of the Union by 1873, though many of the states that had seceded refused to honor the holiday. As the commemoration became more common across America, communities tended to honor all who gave their lives in the service of their country in all wars and conflicts.
The introduction of the sale of artificial poppies to support charities for widows and children of fallen soldiers was instituted following World War I, and was originally inspired by the poem "In Flanders Fields" by John McCrae in 1915. Memorial Day became enshrined in federal law until 1967. The following year the U.S. Congress moved three holidays from their traditional days to the specified nearest Monday so as to grant 3-day holidays to federal workers and others in industries which honor federal holidays. Memorial Day now falls on the last Monday in May by law, which took effect in 1971.
Today Memorial Day is generally observed with the placing of flowers, flags and wreaths on the graves and memorials of military dead as well as family members. Many towns and cities hold parades featuring those in service both military and civil (like fire and police departments), followed by public picnics in local parks.