I first learned "Polly-Wolly-Doodle", a traditional American song, whilst at primary school back in the late 1940's. It was a school-favourite of mine. The lyrics we sang were definitely not politically correct by today's mores. Singing the lines
"Oh, I came to a river and couldn't get across,
Sing Polly-wolly-doodle all the day!
And I jumped upon a nigger, for I thought he was a hoss
would scarcely earn many kudos in our present multi-ethnic global village.
The version that I still sing today can be found in
It's fun to sing
where astonishingly the given lyrics are exactly those that I sang as a schoolchild.