It was an anti-slavery song. I'll be goddamned...Written by Stephen Foster, knew that, in 1852...Inspired by Uncle Tom's Cabin. Huh. Didn't know that. I guess even to an anti-slavery guy "darkies" wasn't offensive in 1852. Whatever, when did it change?

1986?! 

1986 alteration

In 1986, Japanese students visiting the Kentucky General Assembly sang the original version of the song as a gesture of respect. Carl Hines (D-Louisville), a member of the state representative introduced House Resolution 159, which altered the lyrics to amend the word "darkies" to "people" at all official state functions involving the performance of the song.[10]

There's no way. There's no way that song had "darkies" in it till 1986 in the North at least. No way I was playing that song with "darkies" in the lyrics in the mid-'60's. But wasn't that offensive to Robeson, even in 1930? C'mon. Well, he damn well sung it, that's all I know, I just heard it. It must not have been. I'll be damned.