Originally known as Decoration Day, Memorial Day began after the Civil War when families on both sides of the conflict gathered in the spring to lay flowers on the graves of those who had died in the war.

In May 1868, General John A. Logan, the leader of a Union veteran’s group known as the Grand Army of the Republic (GAR), declared that the GAR would celebrate Decoration Day nationally on May 30. Logan chose May 30 because it was a rare day that did not fall on the anniversary of a Civil War battle. It was also a date when flowers across the country would be in full bloom.

Over the years, Decoration Day evolved to a day to honor fallen members of the American armed forces from all wars. It gradually came to be known as Memorial Day. In 1971, Memorial Day became an official Federal holiday. In keeping with the Uniform Monday Holiday Act passed by Congress in 1968, Memorial Day was moved to the last Monday in May.

Cities and towns across the United States host Memorial Day parades each year, often incorporating military personnel and members of veterans’ organizations. Americans also observe Memorial Day by visiting cemeteries and memorials. Some people wear a red poppy in remembrance of those fallen in war—a tradition that began with the World War I poem, In Flanders Fields, written by John McCrae, a Canadian doctor and teacher who served in the war.

Despite the increasing celebration of the holiday as a summer rite of passage, there are some formal rituals still on the books: The American flag should be hung at half-staff until noon on Memorial Day, then raised to the top of the staff. And since 2000, when the U.S. Congress passed legislation, all Americans are encouraged to pause for a National Moment of Remembrance at 3 p.m. local time.

In Flanders Fields

In Flanders fields the poppies blow
Between the crosses, row on row,
  That mark our place; and in the sky
  The larks, still bravely singing, fly
Scarce heard amid the guns below.

We are the Dead. Short days ago
We lived, felt dawn, saw sunset glow,
  Loved and were loved, and now we lie
     In Flanders fields.

Take up our quarrel with the foe:
To you from failing hands we throw
  The torch; be yours to hold it high.
  If ye break faith with us who die
We shall not sleep, though poppies grow
   In Flanders fields.

John McCrae 1872-1918

Sources: American Battle Monuments Commission, History.com, Academy of American Poets