Memorial Day, observed on the last Monday of May, is not just another day to take a day-off from work, have BBQ with friends, or get a special discount while shopping, but a day meant to commemorate the U.S. soldiers who died while serving in the military.

Here are some things that we may not know about Memorial Day though we ought to:

1. Memorial Day, formerly called “Decoration Day”, was first observed by the freed African American slaves in 1865 to remember those who died in the American Civil War.

2. In 1868, General John Logan declared for a nationwide observation of “Decoration Day” on May 30 each year.

3. The term “Decoration Day” had changed gradually to “Memorial Day” and became official in 1967, by the time the occasion was extended to commemorating American soldiers who died in any war.

4. The Congress passed the Uniform Monday Holiday Act in 1968 that moved Memorial Day from May 30 to the last Monday of May, which took effect starting in 1971. There were three other holidays that had their dates changed in 1968 – Washington’s Birthday (from February 22 to the third Monday in February), Columbus Day (October 12 to second Monday in October), and Veterans Day (November 11 to fourth Monday in October, but Veterans Day changed back to November 11 in 1978).

5. The National Moment of Remembrance, where people will pause for one minute as an act of unity, takes place at 3 p.m. local time on Memorial Day.

6. When displaying the national flag, one should fly the flag at half staff until noon – and at noon bring it to full staff.

7. Traditionally, people visit cemeteries and graveyards on Memorial Day to pay respect to the dead.

8. There are approximately 625,000 soldiers who died during the Civil War; 116,516 during World War I; 405,399 during World War II, 53,686 during the Korean War; and 58,209 during the Vietnam War.