Jason & the Legionnaires

Anti-communist Legionnaire political cartoon from 1919

When the American Legion formed in 1919 it was made up of veterans of WWI and was non-partisan. By the mid-1920s, the Legion became an outspoken opponent of communism, a proponent of isolationist policies, and, by 1933, a prominent supporter of FDR and New Deal programs. For the most part, the Legion in the 1930s organized and lobbied on behalf of members to the government.  These efforts included the eventual establishment of the VA. 

Although Jason and the Legionnaires might come off as an ad hoc militia in The Petrified Forest, there is no evidence that other Legion Posts acted this way and is probably a function of melodrama.