So what's with the story?

"This is the story of John Cherokee/An Indian man from the Mirimichi"; Indians in New Brunswick (where Mirimichi is) are mostly Miqmaq or Maliseet. Cherokees belong more properly in US South east, inc. Alabama
"Made him a slave down in Alabam'" An Indian slave? possible but unlikely?
"starved him many a day and night" this seems unlikely (perhaps more typical of Caribbean slaveowners)
"Dug his grave by the old gatepost" -WHO precisely dug his grave? Not the owners (who starved him to death). "Gatepost" reminds me of the role of the lychgates in parish churchyards and their associations with corpses and burial.
"To this day he can be seen/sittin' on the hatch all wet and green" -the first mention of anything nautical, but why is he wet and green (as if he had been drowned)?

These verses are not merely throw-togethers - there is a definite story line here, but it doesn't (quite) make sense. Any suggestions?

My 2c

Jon Bartlett