Columbia subject headings:
Copper miners--Labor unions--Montana--Butte--History.
Socialist parties--Montana--Butte--History.
Working class--Political activity--Montana--Butte--History.
Harvard subject headings:
Copper miners--Labor unions--Montana--Butte--History.
Socialist parties--Montana--Butte--History.
Working class--Montana--Butte--Political activity--History.
Princeton subject headings:
Copper miners--Labor unions--Montana--Butte--History.
Socialist parties--Montana--Butte--History.
Working class--Political activity--Montana--Butte--History.