I didn’t realize the doughnut’s connection to WW1 or Chicago.
What's most interesting about Doughnut Day is its origins. It succeeds a fund-raising event created in Chicago by The Salvation Army in 1938, to help the needy during the Great Depression and honor the women who served doughnuts to soldiers during World War I.
As the story goes, soon after the United States' entry into the war in 1917, the Salvation Army conducted a fact-finding mission in France to see how they might best assist enlisted troops. One conclusion was that soldiers needed canteens or social centers (called "huts") that provided friendly smiles, baked goods, writing supplies and stamps and a clothes-mending service. The huts were established in the U.S. near Army training centers.
About 250 Salvation Army volunteers went to France. There, because of difficulties in providing freshly baked goods from huts established in abandoned buildings near the front lines, volunteers Ensign Margaret Sheldon and Adjutant Helen Purviance are credited with coming up with the idea of providing doughnuts. It's said the sweet rings were sometimes fried in soldiers' helmets. They were an instant hit. Salvation Army records reveal that, after one busy day, Sheldon wrote, "Today I made 22 pies, 300 doughnuts and 700 cups of coffee."