Thing is, I only have to get a few sentences in before I find flat inaccuracies. For example, Medford, Georgia has never laid a claim to the song. There is no Medford, Georgia. The question has always been whether Pierpoint, the son of an abolitionist Unitarian minister, wrote the song in Medford, Massachusetts or Savannah, Georgia.
History on Pierpoint himself seems a little murky, and the article's sources seem murky as well. I don't really see any hard evidence that the song was originally performed in blackface - rather, the author seems to be saying that Pierpoint sold his songs to the minstrel shows, so this would have been one of them. That's not a very compelling case.
Others have claimed that the first performance was for a Sunday school at - wait for it - Thanksgiving. That said, there is also some evidence that the author was not completely in step with his father's views.