A lot of people came to the West to find gold to the point that the population rose dramatically and allowed territories to apply for statehood. Hope this can help :-D
The innovation of American ranching in the west was that herds became so large that keeping them penned into a single location became impossible.
No "Americans" arrived in North America. However, in 10 A.D. Vikings explored the fringes of North America. Also, Native Americans crossed over from Siberia into Alaska over a land bridge about 12,000 years ago. In 1501, Amerigo Vespucci officially discovered America but thought it was Asia so he did not dock. Then in 1592, Christopher Columbus found and docked in the Caribbean and was the first man to land on America.
The main cause is poverty and lack of education. They're very poor, so they can't afford school. If the children do go to school, they drop out very young to work and help earn money for the family. That's not the kind of cycle people can break out of easily.
Add to that the civil war from 1960 to 1996 where the military persecuted the native people, killing up to 200,000, and they've had a pretty rough time of it.
They were afraid of the Soviets powerful army and there goverment