Johnny Cash always had a little bit of a rebellious streak in him, one which conflicted with what was acceptable to many Americans at time. (Think of the famous middle finger or, a few years after this, recording albums at prisons.) One assumes that is one reason why he made this record, aside from a desire to sing these songs (some of which he wrote) and a desire to expose more people to the plight of the indigenous people of the United States, the latter of which is certainly admirable. The record created some controversy, despite its eventual commercial success, which fits in with his desire to piss people off.
If this record was released now I expect there would be a different reaction. Instead of controversy around Cash bring up these issues in the first place – though maybe Fox would go after him for that – there would be controversy over the cover photo – does this qualify as the indigenous version of blackface? – and around the songs themselves, entirely written by white men, one of whom claimed to be part indigenous but which many people now believe was a lie. In essence, the controversy would be around whether or not Cash even has the right to write and sing these songs, as opposed to anger about Cash bringing up the issue at all. (Presumably he was accused of writing and singing about something he knows nothing about by people who don’t want to acknowledge there’s a problem in the first place.)
Everything exists in context; it’s unavoidable. I have listened to a lot of American popular music in my life. I have listened to very little made by indigenous people, particularly the indigenous people of North America. But I can’t think of a single album (or song, even) from 1964 or earlier. Even if we want to censor Cash for dressing like he does on the cover, or for writing songs when he is not native (and for covering songs about natives written by another white guy), at least some consideration should be given to the (likely) fact that virtually nobody sang songs about indigenous experience at the time, certainly not a star of Cash’s fame. The people who did sing those songs were likely folk singers who didn’t get much attention outside of New York. Cash was a major musical figure at the time and he made this album a hit (#2), and took one of its songs to #3 on the singles chart. (That song is now regarded by some as one of the best country songs ever written.)
At the same time as acknowledging this, we can also acknowledge that indigenous popular music performers had virtually no avenues for success in popular music at the time, unless they could pass as someone else.
It’s possible to both be impressed by Cash’s determination and willingness to sing about difficult topics – and to basically will this record into being a hit despite condemnation from the public at large – and also be concerned about the accuracy of La Farge and Cash’s songs (and that cover photo, of course), and to be bothered by the historical context in which only a white man could sing songs about “the American Indian”. Both of these things can be true at the same time.