1866    Memorial Day first celebrated in United States at Waterloo, New York.

1868    Decoration Day (the predecessor of the modern "Memorial Day") is observed in the United States for the first time (By "Commander-in-chief of the Grand Army of the Republic" John A. Logan's proclamation on May 5).

1958    Memorial Day: the remains of two unidentified American servicemen, killed in action during World War II and the Korean War respectively, are buried at the Tomb of the Unknown Soldier in Arlington National Cemetery.

1971    In accordance with the Uniform Monday Holiday Act passed by the U.S. Congress in 1968, observation of Memorial Day occurs on the last Monday in May for the first time, rather than on the traditional Memorial Day of May 30.

1971    In accordance with the Uniform Monday Holiday Act passed by the U.S. Congress in 1968, observation of Memorial Day occurs on the last Monday in May for the first time, rather than on the traditional Memorial Day of May 30.