Several South American cities that had at least 4.0 million residents were not mapped. All of them started with fewer than 2.0 million residents in 1900. One of them, Buenos Aires (a province-level city within a province of the same name) had between 10.0 and 19.999 million metropolitan residents in 2012. Its growth was due in part to national population growth and in part to urbanization. The metropolitan area now incorporates nearby growing cities. It also grew due to its being a national capital and a center of industry and commerce. (The area is not mapped for any period.)
The other cities, the ones that ended between 4.0 and 9.999 million metropolitan residents, are: Bogotá (Colombia), Lima (Perú), Santiago (Chile), Caracas (Venezuela), and Salvador (Bahia). (None of these areas are not mapped for any period.)