On the first Decoration Day, General James Garfield made a speech at Arlington National Cemetery, and 5,000 participants decorated the graves of the 20,000 Union and Confederate soldiers buried there.
The first state to officially recognize the holiday was New York in 1873. By 1890 it was recognized by all of the northern states. The South refused to acknowledge the day, honoring their dead on separate days until after World War I (when the holiday changed from honoring just those who died fighting in the Civil War to honoring Americans who died fighting in any war).
It is now observed in almost every state on the last Monday in May with Congressional passage of the National Holiday Act of 1971 (P.L. 90 – 363). This helped ensure a three day weekend for Federal holidays, though several southern states have an additional separate day for honoring the Confederate war dead: January 19th in Texas; April 26th in Alabama, Florida, Georgia, and Mississippi; May 10th in South Carolina; and June 3rd (Jefferson Davis’ birthday) in Louisiana and Tennessee.