More nonsene has been written about this song, I think, than any other in Mudcat. There is no evidence of the song prior to the 1830s, under any of its names. I can concede an origin during the Napoleonic wars, that would provide a logical beginning.
The tune should be considered separately with regards to age, but (earliest printing 1825? see Bruce O in the Origins thread) nothing in the 18th C. music collections.

I agree with Guest on his remark about 'authenticity' and time and place; all versions from the 'first' to the one my neighbor might sing in his bath have their right to existence.