From Bunker Hill to Pork Chop Hill, from Shiloh to Tarawa, from the Battle of Antietam (the deadliest single-day battle in U.S. history) to brief, nameless skirmishes that will never find their way onto the pages of a history book, there’s no denying the sacrifice that the men and women of America’s armed forces have made, and continue to make, for this nation.

Estimates vary, but it’s safe to say that at least 1.2 million American soldiers gave that last, full measure of devotion for their country in the past 248 years. They marched out, or were helicoptered out, to the battlefield, and never returned. They were shot out of the sky, or went down with their ship.

While there are other holidays to honor those that put on the uniform (Veterans Day, Armed Forces Day), there is only one day specifically set aside to remember those that didn’t come back from war—Memorial Day.

It is fitting that Memorial Day has its roots in the immediate aftermath of America’s bloodiest conflict—t...