"Nigra" was acceptable - "good" negro or a negro who was your buddy even if you were white was a 'nigra'.
If you were 'useless' - not a workable farm worker you were the other "N" word.
Whites I knew differentiated between "nigra" and "n word".
The "n word" was used despairingly by whites AND blacks. I don't know what is acceptable terminology now as I left the farm many years ago.
I, too, grew up on my aunt’s farm, and her neighbors were a very pleasant extended black family. My Uncle Tom, yes that’s his real name, used to say, “They are some of the finest negroes I’ve ever met,” and he would often tell James, the eldest black man in the family, “You, sir, are a fine negro, and I am proud to know you.” It was never seen or taken as an affront or offense.
On the other hand, the inbred hillbillies up the road from the farm couldn’t differentiate a cow from a sow and often referred to the very successful black family farm disparagingly, and we understood to never use the “n word” for any reason. Negro, however, was acceptable, and it was only until I was older and actually learned Latin and studied anthropology that I understood where it came from as a racial classification.