I had meant to continue on with the general description of peoples and places, but having run out of direction previously, it seemed good to post what I had and then pick up the subject again today. Since, too, people have given me a direction, namely the migration of elves from the 'new' world to the 'old' world ... or the reverse, from the elven perspective. Just to keep things clear, for the remainder of the post the "New World" will be the Americas; the "Old World" will be the Eurasian-African continent.
Just as humans likely evolved in one part of the world, then migrated outwards, so too have elves, dwarves, gnomes, orcs, goblins and a variety of other races in my world. They have all started in one specific place of origin and spread outwards, eventually competing for lands where their migration pattern interceded with the migrations of others.
For example, I have said previously that dwarves existed in the mountain knot of the Altai Mountains about 11,000 BCE. I also have said that the gnomes arose from the Svirfneblin, who dwelt under the Scandinavian mountains at approximately the same time. And Wednesday I said the Elves had arrived in Scandinavia about 3,000 years later. By that time, humans had long expanded out of Africa into the rest of the Old World ... into the Middle East 125,000 years ago, and - with many disputed dates - had expanded into the Indian subcontinent, Indochina, Southern China and Europe over the next 50,000 years.
But while I say that these other cultures, dwarves, gnomes and elves, existed as cultures at those times above, that is to say the time when they had become evolved hunter/gatherers & farmers (albeit in a different sense), comparative to human neolithic cultures. Just as there were human paleolithic cultures, there were also dwarven and elven examples (gnomes precluded, as the svirfneblin developed below ground). As well, there were numerous other violent proto-humanoid cultures, cave-orcs, cave-gobs, cave-ogres and so on, who rose in various mountain ranges, boreal forests and deserts (before they became full deserts) alongside a considerable array of intelligent, but technologically stilted minor cultures, such as the faeries, dragons, naga, kenku, lizard men, rakshasa, yeti and so on. Where you can postulate the rise of considerably different humanoid races - and you choose not to adopt the ever-present convenience of every race arising from a single biological source - you're left with an incredible hodgepodge of migrations pushing outwards and being pushed back on hundreds of fronts that real humans in the real world never experienced.
Thus, there was no prehistoric expansion of humans into the forests of Russia or Siberia, and therefore no human progression into the New World, and therefore no native American Indian cultures, no Aztecs, Mayans or Incas - not human, at least - nor any human Polynesian expansion into Australia or the Pacific Islands, so all those lands are held and civilized by races that - in some cases - haven't been discovered yet.
Where I looked at the world map, to decide where the elves would naturally arise, the best most logical place - it seemed to me - was the great deciduous forest of the Eastern United States. Lightly inhabited in the 17th century, it struck me as particularly fanciful to imagine a powerful "native" culture of Elves dwelling in those lands, so that yes, of course, the Hurons and the Iroquois exist ... only they are magic using, far more civilized cultures made of elven peoples, who keep the French, English and other Europeans firmly compressed against the eastern seaboard. There have been violent wars, yes, with the Narragansett and the Seminoles, but those peoples have managed to hold their own to some degree, and now they keep a tenuous peace with human cultures who know better than to believe the wilderness upon the mountains is theres for the taking. Thus, there could never be any 'America' in the sense that Americans comprehend (no 'Canada' either, but somehow that doesn't bother me as much as an impossible America would bother Americans), because in fact the native cultures "won" those early power struggles ... even if the natives were another race.
I far preferred the meso-American cultures to be anything but elf, however, as I like the idea of a Spanish Main and because it helps keep a more consistent historical balance for actual human history in Europe. Thus, the Mayans, the Olmecs, the Aztecs and the Incas were various reptile-humanoid cultures, rising in the jungles of Mexico through South America, less magically developed and therefore less able to resist Spanish incursions. Still, I wouldn't want the Incas to fall like their human counterparts did, so there are still anti-Spanish areas, where there still IS an Incan culture and an ongoing battle line between what the Spanish can maintain and what they still wish to consume. All that, I believe, would make a number of interesting bloody adventures for a party that wanted to pursue a genocidal campaign (or help lizard/snake creatures fight back the Europeans, whatever floats a boat).
Too, I've already described numerous non-human peoples in Africa, who certainly could not have been there when humans began expanding 125,000 years ago - not if I still want a European, Indian or Chinese world. It must therefore be presumed that these races are new, that they have arisen since humans, probably from small pockets where humans never penetrated, or from the vast Congolese jungle - which I see inhabited mainly by an Edgar Rice Burroughs like culture of Kenku. I have always loved those budgie-like humanoids, who after 40 million years of evolution managed to keep their feathers while losing the ability to fly in exchange for stronger, bulkier legs and bodies, the strength to wield weapons and a natural environment that provided for access to tin, copper, iron and zinc (modern Congo/Zaire), producing a reasonably advanced race of humanoids to exploit that jungle. The Kenku, of course, defeated those human tribes that we know, probably violently and heaping up great mounds of bodies, etcetera, typical scenes of history, perhaps around the time of the ancient Hittites. That was only 3,500 years ago.
The jackalwere of the Kanem Empire I described in my world might have been only a few small tribes around Lake Chad at that time, who experienced a sudden rush of expansion, possible inbreeding with some other tribe ... or even finding themselves possessed of a kind of lycanthropy, which re-engineered their biological make-up around 500 AD, resulting in the decimation of human tribes who had settled along the Sub-Sahara, but whom had never become particularly advanced. Only the Mali, whose power was improved by the existence of Tombouctou - which historically had a highly advanced culture only because the Niger Swamp in southern Mali was a natural source for papyrus, just as the Nile Delta had been - could withstand the expansion of the jackalwere Kanem-Bornu empire. For all I've decided, the Bornu could be another race of humanoids, wererats, who exist as a sub-strata of the jackalwere society, like the Helots did to the Spartans. Only the party daring to enter into that environment would know for sure.
So the field is wide open. I like the idea of rakshasa being small, obscure pockets in the highlands of Nepal, Kashmir or Tibet, perhaps the true source of Buddhism, predating Siddhartha by a thousand years. The naga might have the same relationship with Hinduism, dwelling upon various obscure islands in the East Indies, from the Andamans in the Bay of Bengal all the way to New Guinea. Perhaps a cult-society of Ki-rin live in the mountain fastnesses above the source of the Mekong River; perhaps there are Githzerai in monasteries in the Tien Shan mountains between Kirghizia and Tibet, or perhaps Githyanki on the deserts of east Kazakhstan or Sinkiang. I see a great Norker kingdom in place of Yakutsk; flind pirates encircling the Sea of Okhotsk; a Urukai orc empire of the Amur River, or hobgoblins in the forests of Irkutsk. Vast, lightly occupied areas nevertheless closed to human investigation, where armies of tens of thousands may occasionally be drawn together to make war on China, or great navies that raid the coast of Hokkaido.
Everything fits together like a puzzle; and each part of the puzzle is neatly supported by the actual earth comparison, so long as it's viewed through the simple lens that these people are not 'people,' they're elves, they're tabaxi, they're gnolls or bug bears. Then there's no need to build a complete history from scratch ... one can tweak and adjust and fit the actual history to the peculiarities of the race in question, giving a basis for depth and motivation where one's imagination might otherwise fall short. Of course there's room for creativity - everything above has been creative. But there's also room for a crutch or two to the mental faculties.
Better face it - there's too much here to invent. A little help is always appreciated.