UPDATE.....Oops, It looks like Leendert beat me to it. We found some of the same links. I will leave this here for now.
It may depend on exactly when they went though the training, but in the late 1950s, I believe the primary school for helicopter training was at Fort Wolters in Texas and the advanced school was at Fort Rucker in Alabama. Later all training was consolidated at Fort Rucker (where it still is today). H-19 training, which was in the advanced phase, would have been done at Fort Rucker.
There is an article on training history here:
https://www.airspacemag.com/history-...ers-180956245/
There is an old 1956 army training film on how to fly the H-19 and the opening scene shows Fort Rucker:
https://www.youtube.com/watch?v=WIIbql4GLZo
Fort Wolters:
http://www.fortwolters.com/USAPHS.html