In 1917, the original "Salvation Army Doughnut" was first served by the ladies of the Salvation Army during World War I.
The Salvation Army sent a fact-finding mission to France. The mission concluded that the needs of US enlisted men could be met by canteens/social centers termed "huts" that could serve baked goods, provide writing supplies and stamps, and provide a clothes-mending service. Typically, six staff members per hut would include four female volunteers who could "mother" the boys. These huts were established by The Salvation Army in the United States near army training centers.
About 250 Salvation Army volunteers went to France. Because of the difficulties of providing freshly baked goods from huts established in abandoned buildings near to the front lines, the two Salvation Army volunteers (Ensign Margaret Sheldon and Adjutant Helen Purviance) came up with the idea of providing doughnuts. These are reported to have been an "instant hit", and "soon many soldiers were visiting The Salvation Army huts". Margaret Sheldon wrote of one busy day: "Today I made 22 pies, 300 doughnuts, 700 cups of coffee."
National Doughnut Day started in 1938 as a fund raiser for Chicago's The Salvation Army. Their goal was to help those in need during the Great Depression, and to honor The Salvation Army "Lassies" of World War I, who served doughnuts to soldiers.
In the Second World War, Red Cross Volunteers also distributed doughnuts, and it became routine to refer to the Red Cross girls as Doughnut Dollies as well.