I believe the demand for automobiles in the 1920s stimulated growth in many other industries. Think of the other things that came after automobiles. ;)
The most widely accepted theory on how early humans migrated to North America is the one that raises that the first settlers of North America crossed from Siberia through the Bering Strait.
For 19,000 years there was the possibility that the primitive tribes of Asia could cross the Beringia bridge. The first one to compose a possible migratory model of Asians to America through Beringia was Caleb Vance Haynes in an article published in the journal Science in 1964.
The most important data to establish a migratory theory during the last glaciation is the fact that Canada was completely covered with ice during the last glaciation, invaded by two gigantic plates: the laurentine ice plate and the ice plate of the mountain range. This made it impossible to enter the continent beyond Beringia.
A theory was then developed: shortly before the end of the last glaciation and the Beringia bridge was flooded, the edges in contact of the two large ice sheets covering Canada began to melt, opening an ice-free corridor of about 25 km wide, which followed, first the valley of the Yukon River and then the eastern edge of the Rocky Mountains along the Mackenzie River corridor. Scientists who hold the theory estimate that this occurred in 14,000 BC, although others question the date and claim that it could not have happened until 11,000 BC. At that time the human beings who were in Beringia could move towards the interior of America although there is still no physical evidence to prove the fact itself.
This theory was articulated with the discoveries of the Clovis culture that dated from the year 13,500 BC to conclude that it had been integrated by the first migrants that entered by the bridge of Beringia, which in turn would have descended all the other cultures indoamericanas.
The correct answer to this open question is the following.
The Tiwanaku and Wari states had ruling classes but no dynasties and central bureaucracies because they based their ruling in the strength of their military and the expansion of their territories. They were not interested in a bureaucratic form of government. What they did was to manage the control and operation of these territories using a collaborative form of government that had autonomy in each region to make decisions according to the particular issues on the locality. For that to happen, these people segmented their territories in a very "raw" or elemental form of federation. These patterns expressed the territorial organization of these states. And for years they prospered and grow, with the domination of those lands in the Andes.
