The melody is certainly evocative, but it's not an American melody. It was written only a year after Dvorak came to the US, and was inspired by, but not really based on Black and American Indian music that he'd heard(which he thought sounded a lot alike)--the underlying pulse to the melody is definitely not that of a spiritual--it is more like a Czardas--some claim the melody was in fact an existing Bohemian folk tune.

Be that as it may, if you ever play at a Hungarian Wedding, and they call for a Czardas, try this tune--it works a treat--