Joel Chandler Harris, in his introduction to "Uncle Remus, Myths and Legends...," 1880, quotes from Herbert H. Smith, author of "Brazil and the Amazons":
"One thing is certain. The animal stories told by the Negroes in our southern states and in Brazil were brought by them from Africa. Whether they originated there, or with the Arabs, or Egyptians, or with yet more ancient nations, must still be an open question. Whether the Indians got them from the Negroes or from some earlier source is equally uncertain. We have seen enough to know that a very interesting line of investigation has been opened."
Harris goes on to quote a story from Hartt's book, "Amazonian Tortoise Myths," which is close to to a Brer Rabbit-Brer Cooter (terrapin) story which Harris collected from the Sea Islands.
Correspondence with Powell and others at the Smithsonian added to his familiarity with similar stories from other cultures.

Harris was very careful to reproduce the dialect common in Georgia at the time of collection of the stories or legends, and comments that his later character sketches were different; marking the modification which the speech had undergone "even where education has played no part in reforming it." Writing in 1880, he said "Indeed, save in the remote country districts, the dialects of the legends has nearly disappeared." In the legends, Harris, careful scholar, has "endeavored to preserve the legends" in the form in which he found them, although also trying to make them understandable to the public.

It is unfortunate that most people who mention the legends and songs have no knowledge of the man who collected them and the great service he performed by not only preserving them, but keeping the dialect of the region in which they were found so that it could be studied by linguists interested in the American language, its dialects and its evolution.
In another thread, the tarbaby story is discussed; Harris knew of its occurrence elsewhere but I can't remember the comments.