To all well-meaning civilians: Please do NOT wish 'A HAPPY Memorial Day'. It is a solemn day of remembrance of those who held the line, stood the watch, and paid the price! 'A Blessed Day' is just fine. Because though we are bought back in Yeshua's, we are blessed in the fallens'! -JP

Memorial Day (originally known as Decoration Day)[1] is one of the federal holidays in the United States for honoring and mourning the U.S. military personnel who died while serving in the United States Armed Forces.[2][3] It is observed on the last Monday of May. Memorial Day is also considered the unofficial beginning of summer in the United States.[4]

It is a day for visiting cemeteries and memorials to mourn the military personnel who died in the line of duty. Volunteers will place American flags on the graves of those military personnel in national cemeteries.[5] Others such as family and friends will also come to lay flowers and grieve on the graves of those who died in the US military.

The first national observance of Memorial Day occurred on May 30, 1868.[6] Then known as Decoration Day and observed on May 30, the holiday was proclaimed by Commander in Chief John A. Logan of the Grand Army of the Republic to honor the Union soldiers who had died in the American Civil War.[7] This national observance followed many local observances which were inaugurated between the end of the Civil War and Logan's declaration. Many cities and people have claimed to be the first to observe it. However, the National Cemetery Administration, a division of the Department of Veterans Affairs, credits Mary Ann Williams with originating the "idea of strewing the graves of Civil War soldiers—Union and Confederate" with flowers.[8]

Official recognition as a holiday spread among the states, beginning with New York in 1873.[8] By 1890, every Union state had adopted it. The world wars turned it into a day of remembrance for all members of the U.S. military who fought and died in service. In 1968, Congress changed its observance to the last Monday in May, and in 1971 standardized its name as "Memorial Day".

Two other days celebrate those who have served or are serving in the U.S. military: Armed Forces Day, which is earlier in May, an unofficial U.S. holiday for honoring those currently serving in the armed forces, and Veterans Day on November 11, which honors all those who have served in the United States Armed Forces.[9]

https://en.wikipedia.org/wiki/Memorial_Day