Take a look back at the sweet history behind the occasion.
A tray of sprinkled glaze, chocolate, and cinnamon sugar donuts in celebration of National Donut Day 2018
Celebrate National Donut Day 2018 by learning about the unofficial holiday's sweet history.
| Credit: Scott Grummett/Getty Images

Today is National Donut Day, which means there are free donuts to be found at Dunkin' Donuts, Krispy Kreme, and many local chains and smaller donut shops across the U.S.

But what you might not know is that National Donut Day, the unofficial holiday celebrated on the first Friday of June every year, has a history just as sweet as the dessert itself.

Started by The Salvation Army in Chicago in 1938, the roots of National Donut Day trace back to 1917, when The Salvation Army sent 250 volunteers to France to provide support to U.S. soldiers stationed there for World War I.

Salvation Army volunteers give fresh donuts to soldiers in France in 1918 T
The Salvation Army volunteers give out fresh donuts to soldiers from front line huts in France in October, 1918.
| Credit: Historical/Getty Images

The volunteers were brought in to serve soldiers everything from clothing and supplies to baked goods, but limited rations and lack of household goods made providing an array of sweets tricky — until two of the volunteers got creative.

Using the simple ingredients they had, which included flour, sugar, baking powder, cinnamon, lard, and canned milk, volunteers Ensign Margaret Sheldon and Adjutant Helen Purviance came up with the idea of making donuts for the soldiers, using their hats to fry them and coffee percolator tubes to cut the donut holes.

The dessert became such a hit that the women serving them became known as Donut Lassies, and the tradition carried on through World War II.

Two Salvation Army
Salvation Army donut lassies hand out fresh donuts to U.S. soldiers in 1919.
| Credit: Smith Collection/Gado/Getty Images

The Salvation Army created the first Donut Day event in 1938 in Chicago, as a way to both honor the Donut Lassies and raise funds during the Great Depression. The celebration has continued on since that day.

Today, those who want to take a trip back in time can whip up a batch of the original donuts created by the Donut Lassies themselves with this donut recipe from the Salvation Army.