It sounds like a consumer holiday created as an excuse for us to stuff some unhealthy food down our gullets. But National Doughnut Day, which is marked on the first Friday of June, has actual historic roots.

The Salvation Army coined the unofficial holiday in 1938 to commemorate the female volunteers who served doughnuts and coffee to soldiers during World War I.

In fact, the group's effort is credited with first popularizing doughnuts with American consumers.

But even if you haven't served on the front lines, there are still several places where you can treat yourself today. Time reports that participating Krispy Kreme stores are offering one free doughnut to any customer, with no purchase necessary. Dunkin' Donuts has a similar deal but with a catch: Their stores are also offering a free pastry but you have to purchase a beverage.

The site lists a few other competing doughnut deals various other retailers are offering as well. In New York City, Mayor Michael Bloomberg will declare an official proclamation marking Entemann's creation of the largest box of doughnuts in history. The company will also be unveiling a doughnut that is 1-foot in diameter.

This video, produced by the Salvation Army, has some more details on the history of National Doughnut Day:

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