This coming Monday we will celebrate Memorial Day. For most of us the one-time Decoration Day is part of a three-day holiday that marks the start of summer. It’s a time for shopping, barbecues, picnics and street fairs, a Monday off when most of us will sleep late and revel in our unaccustomed leisure.

It’s easy to forget the reason the holiday originally known as Decoration Day first came to be. In 1868, three years after the Civil War had ended, Arlington National Cemetery, across the Potomac River from Washington, D.C. already held the remains of 20,000 Union dead and several hundred Confederate dead. The head of an organization of union sailors and soldiers called for setting aside a day when the graves of Civil War dead would be decorated with flowers. Major General John A. Logan declared “Decoration Day” should be May 30.

The idea spread and by the end of the 19th century, Memorial Day ceremonies being held on May 30 throughout the nation, with many state legislatures passing laws making the day an official holiday. Only after World War I, however, was Memorial Day expanded to honor the dead of all American wars. In 1971, more than a century after the first Decoration Day, an act of Congress scheduled Memorial Day on the last Monday in May and made it a national holiday.

Another tradition arose in those years after the Civil War when the concept of Decoration Day was still in its infancy. Women in Columbus, Mississippi in April 1866 decorated the graves of Confederate soldiers who had died at Shiloh. Union soldiers were buried nearby, their graves neglected—these were, after all, the enemy. The sight of the bare Yankee graves disturbed the good women of Columbus, Miss. so they placed some of their flowers on those graves, as well. The enemy had died for a cause they believed in, and that sacrifice had fully earned a flower or two.

This year, sadly, we have more dead to mourn and remember. The death toll for Americans killed in conflict in Iraq since March 2003 has surpassed 1,600, and American soldiers are as we speak giving their lives for freedom in that Middle Eastern country, in Afghanistan and in many other trouble spots around the world.

Whatever opinion we may hold of the conflict in which a soldier died, the fact remains that this was a death sustained by someone with the deep-seated conviction that one’s country and the ideals on which it was founded are worth whatever sacrifices must be made. To ensure that one’s country is worth living in, the graves of America’s war dead tell us, we have to be willing to die for it.