I found (and sang) this song from an old book at my grandma's house in Wisconsin. 1954, I was about 5. The lyrics with the n-word were there for sure -- likewise in a Boy Scout song book. I have a copy of "Heart songs-- Melodies of Days Gone By." (Songs dear to the American People) Initiated by the National Magazine. Contributed by 25,000 people. Copy write 1909 the Chapple Publishing Ltd. Boston, Mass, USA. In includes "Polly Wolly Doodle with no attribution given for tune or lyrics. Those who contributed songs gave their historical association with the song, but these were not published with the songs. Nicely, the book has photos of many popular singers of the day. This book has the lyrics with the n-word in verse 3 of 7. It includes the advise, "and so on, ad infin" after verse 7. My father (a British pastor) strongly discouraged us from singing the n-word.