The site bio of WG doesn't add much in answer to Cluin's original question, except to say that, " He performed with Burl Ives and Woody Guthrie for migrant farm workers during the Depression and continued working for the good of all until his death in 1978."
It'd be more than fun to know more about how those then-young guys went about that, what they performed and sounded like, how they were received, what they learned, what they believed they were doing, no ?
They were all word people. Did any of them write about it ?