"Could not agree more, Joe G."
I think I made it clear tht this is my view too, but I would like to clarify that
The 'language' at the time these songs were made may have been racist but this doesn't automatically mean that the intention of the song was - that was the way things were expressed "in the bad old slavery days"
I've heard good versions of both 'The Flying Cloud' and 'The Banks of the Nile' containing racist language; in the latter it says "To fight the blacks and heathens on the Banks...."
I've adapted it to 'Fight another battle", but somehow, it seems to lose its visual strength - I've learned to live with that
The song was given to us by an old farm-worker, Pat MacNamara, one of the kindest and most tolerant men we met, without a racist bone in his body; he sang it all his long life without having thought about it
We got the same song from a now long-dead lady from this town (about Ten miles south from Pat's home-place), Nora Cleary, she was of similar friendly character to Pat
Nora's version uses the "n" word in the same line)
I'm a singer who also researches - I would edit the songs if I sang them (or not sing them at all), but I would document and archive them as we received them - they are important songs which carry essential parts of our history - part of that history is the vernacular that gives a fuller picture of the people who sang the songs - warts and all

I know there were overtly racist songs made at certain points of our histories, particularly 19th century Anti-Irish ones made in America by organisations set up to oppose the flood of immigrants fleeing the famine, but as far as I know, few survived in the repertoires of singers
I can see no reason do dredge them up from 'the dustbin of history' other than for historical information   

I've always been careful and somewhat reticent in editing the songs I sing, not because of any 'purism' but for fear of losing something, both from the superbly concise language of our folk songs, and from the minute details of information they often carry
Jim