I was confused myself at first, but then I came across a post that actually confirmed it (or more of a trying-to-say-it-isn't-true-but-was-soon-debunked).
"National Doughnut Day started on June 7, 1938 when a young military doctor by the name of Morgan Pett was sent to a military base. On his way there he stopped at a bakery and picked up 8 dozen doughnuts. When he arrived at the base he started helping many wounded soldiers, and would give them a free doughnut. One man he helped was a Lieutenant General by the name of Samuel Geary. Samuel Geary greatly appreciated the help on his leg, and the doughnut (as he was a very comical man) so he decided to make a fund raiser with Morgan Pett to give every wounded soldier, and the needy a doughnut. This fund raiser was later joined with the Salvation Army. Soon after the US entrance into World War I in 1917, 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." (snippet from the wiki article on it)