When the Civil War ended in April 1865, Americans struggled to cope with the unprecedented loss they had experienced as a nation. Because the end of the war had come in the spring, communities began decorating soldiers’ graves with fresh flowers. Such “Decoration Day” rituals began popping up across the country on different days. In the South, many chose May 10, the anniversary of Stonewall Jackson’s death; April 26, the day of the final Confederate surrender; or June 3, Jefferson Davis’s birthday.
Northerners also chose a spring day for formal commemoration of the dead. In 1868, General John Logan, Commander-in-Chief of the Grand Army of the Republic, officially designated the 30th of May “for decorating the graves of comrades who died in defense of their country.” By the end of the 19th century, most Northern states had adopted the holiday.
One of the earliest known celebrations of what we now know as Memorial Day took place in Charleston, South Carolina on May 1, 1865, when the city’s freed Black residents organized a proper burial for hundreds of Union soldiers who had died in a Confederate prison, followed by a parade to honor their memory.
A century after General Logan’s declaration, President Lyndon Johnson signed legislation making Memorial Day a federal holiday, changing the observance to the last Monday in May and standardizing the name as “Memorial Day.”
Source: American Experience.wgbh.org