An incidental observation:- The famous director John Ford liked to use particular folksongs as sort of background leitmotivs for his films: much use of 'Garryowen'e.g. for films about the US Cavalry, & even a western called "My Darling Clementine' with an obvious background motif. 'Red River Valley' makes many appearances on the soundtrack of perhaps his greatest film,'The Grapes of Wrath', a story of dustbowl migrants set on the Oklahoma-California journey so many such took in the 1930s.