Memorial Day is a federal holiday in the United States for remembering the people who died while serving in the country’s armed forces. The holiday, which is observed every year on the last Monday of May, originated as Decoration Day after the American Civil War in 1868, when the Grand Army of the Republic, an organization of Union veterans founded in Decatur, Illinois, established it as a time for the nation to decorate the graves of the war dead with flowers.

By the 20th century, competing Union and Confederate holiday traditions, celebrated on different days, had merged, and Memorial Day eventually extended to honor all Americans who died while in the military service. It typically marks the start of the summer vacation season, while Labor Day marks the end.

Many people visit cemeteries and memorials and many volunteers place an American flag on each grave in national cemeteries. Memorial Day is not to be confused with Veterans’ Day; Memorial Day is a day of remembering the men and woman who died while serving, while Veterans’ Day celebrates the service of all U.S. military veterans.

The practice of decorating soldiers’ graves with flowers is an ancient custom. They were decorated in the U.S. before and during the American Civil War. A claim was made in 1906 that the first Civil War soldier’s grave ever decorated was in Warrenton, Virginia, on June 3, 1861, implying the first Memorial Day occurred there. There is authentic documentation that women in Savannah, Georgia, decorated Confederate soldiers’ graves in 1862.

The sheer number of soldiers of both sides who died in the Civil War, more than 600,000, meant that burial and memorialization took on new cultural significance. In 1863, the cemetery dedication at Gettysburg, Pennsylvania, was a ceremony of commemoration at the graves of dead soldiers. Local historians in Boalsburg, Pennsylvania, claim that ladies there decorated the graves on July 4, 1864.

As a result, Boalsburg promotes itself as the birthplace of memorial Day. In 1865, the federal government began creating national military cemeteries for the Union war dead.

During the Civil War, Union soldiers who were prisoners had been held at the Hampton Park Race Course in Charleston; at least 257 prisoners died there and were hastily buried in unmarked graves. Together with teachers and missionaries, black residents of Charleston organized a May Day ceremony in 1865, which was covered by the New York Tribune and other national papers. Nearly 10,000 people, mostly freedmen, gathered on May 1 to to commemorate the war dead. Involved were about 3,000 school children,newly enrolled in freedmen’s schools, as well as mutual aid societies.

David W. Blight described the day: “This was the first Memorial Day. African Americans invented Memorial Day in Charleston, South Carolina. What you have there is black Americans recently freed from slavery announcing to the world with their flowers, their feet and their songs what the war had been about.

What they basically were creating was the Independence Day of a Second American Revolution.” However, Blight stated he “has no evidence” that this event in Charleston inspired the establishment of Memorial Day across the country.

On May 26, 1966, President Johnson signed a presidential proclamation naming Waterloo, New York, as the birthplace of Memorial Day. Earlier, the 89th Congress had adopted House Concurrent Resolution 587, which officially recognized that the patriotic tradition of observing Memorial Day began one hundred years prior in Waterloo, New York.

Other communities claiming to be the birthplace of Memorial Day include Boulsberg, Pennsylvania, Carbondale, Illinois, Columbus, Georgia and Columbus, Mississippi.

By 1890, the remains of nearly 300,000 Union dead had been reinterred in 73 national cemeteries, located near major battlefields and thus mainly in the South. The most famous are Gettysburg National Cemetery in Pennsylvania (shown here) and Arlington National Cemetery near Washington D.C.

Memorial Day speeches became an occasion for veterans, politicians and ministers to commemorate the War and, at first, to rehash the “atrocities” of the enemy. They mixed religion and celebratory nationalism and provided a means for the people to make sense of their history in terms of sacrifice for a better nation.

According to the White House, the late May date was chosen as the optimal date for flowers to be in bloom.