These 15 regions are quite natural, distinguished by peculiar physical, and geological features; but they do not coincide with the ethnological regions, where the American tribes have spread and intermixed. It would be difficult to state here even the most striking of these last. It will be the aim of this work to seek for them, and ascertain their limits; which have often varied anciently: while in modern times the European colonies and states have invaded them in all directions. Meantime the population of both Americas, must be distinguished in ancient and modern. In proceeding from the known to the unknown: we ascertain that a multitude of nations have come to America since 1492, as colonists or visitors. The principal were 1. _Spanish_: who have colonized or conquered from New Mexico to Chili, and from Florida to Buenos Ayres. But they came not alone, and have brought along with them as auxiliaries. 1. Italians, 2. Flemish, 3. Biscayans, 4. Canarians, &c., while as slaves 5. Moors of Mauritania, and 6. Many African-negro nations. 2. _Portugueze_: who have colonized the whole of Brazil, and brought there besides many Negro nations, some Moors, Gypsies, Chinese, &c. 3. _English_: Who have colonized the whole eastern side of North America, Jamaica and other islands of Antilles, with parts of Yucatan, Honduras, Guyana, &c. But they have brought with them, the Welsh, Scotch, Irish, Germans, Jews and many African nations. 4. _French_: They colonized Canada, Lousiana, Hayti, several Carib islands, Cayenne in Guyana, &c., and although conquered in North America and Hayti, their language remains. They brought along the Provençals, Bretons, Basks, speaking distinct languages, with several African nations. 5. _Scandinavians_: Who partly settled in North America since the 10th century, did laterly colonize again Groenland, with Delaware and some Carib Islands. They include the Norwegians, Danes and Swedes. 6. _Dutch-Hollanders_: Sent colonies to New-York, Surinam, Curazao, &c. brought Gypsies, Germans and Africans. 7. _Russians_: Have invaded and partly settled the north west shores and islands of North America; bringing there Cozacs, Calmucs, and several other Tartarian subjects. 8. Besides these, several other nations have laterly visited America, or settled therein, blending with the above. All the nations of Europe, even Hungarians, Polanders, Greeks and Turks, have been brought there. Pirates of all nations, even Algerines, have wandered to America. Almost all the nations of Africa have been led there in slavery. Asia has sent Jews, Hindus, Gypsies or Zinganis, Chinese and Tartars: while Oceania has sent Malays, Madagascars, Hawayans, &c. This well known fact of the various and anomalous modern population of both Americas within 3 or 4 centuries, will greatly help us to form a more correct estimate of the ancient population and colonization of such vast countries during many thousand years previous to 1492.