Negroland

Negroland, or Nigritia was a term Europeans used to describe a region in Africa, south of the Sahara. The region was poorly explored, and Europeans mainly knew the area around the coast. The name was probably a direct translation of the Arabic term "Bilad al-Sudan", which translates to "land of the Blacks".
As can be seen on the map, Europeans of the time believed that the rivers Senegal, Gambia and Niger were in the same river system: one river that divided before flowing into the ocean. 
In 1823, approximately the same area was described as "Nigritia" on an American map published by Fielding Lucus Jr. The inhabitants of Nigritia were called Negroes.