Memorial Day was first observed by former slaves in Charleston, South Carolina at the Washington Race Course (now known as Hampton Park). It was on May 1, 1865 that a crowd of up to ten thousand showed up to observe and honor the fallen Union soldiers during the Civil war. It did not include other soldiers until after World War I.
It was in 1868 that the holiday was celebrated nationwide. The “Decoration Day” was to be observed on May 30th of every year. This date was chosen because it was not the anniversary of a battle.
Many of the states in the south refused to celebrate Memorial Day because of the lingering animosity towards the Union Army. Only Columbus, Mississippi honored the holiday. This was because they had both Union and Confederate soldiers buried in their cemetery.
Memorial Day was known as Decoration Day up until 1882. And it was not a Federal law until after World War II. It was at this time the date was changed as well. Instead of being celebrated on May 30th of every year, it was moved to the last Monday in May.
It is a holiday to honor our fallen soldiers. Many people visit cemeteries and memorials. And there is a national moment of remembrance at 3pm local time. Another tradition is to fly the American flag at half-staff from dawn until noon. You will also see flags at grave sites in National Cemeteries.