The original version of Showboat.
Which version of Showboat? The 1929 version or the 1936 James Whale film with Paul Robeson? The latter is great and is actually much less racist than the awful 1951 MGM version.
If by the original you're referring to the one Irene Dunne starred in, it was extremely politically incorrect.
Especially when Dunne imitates the slow moving, foot shuffling and eye rolling negro stereotype. It would send the PC Nazis into hysteria.
You'll never see it again except on DVD/VHS.