Most tribes were self-sufficient and did not need to unite to form larger groups. Feeding a larger population would also cause problems for the tribe and the wildlife around them. Too many people and the tribes would be forced to hunt more, The more they hunt the larger impact they have on the environment and ecosystem.
Isolation wasn't a factor of why Native Americans didn't unite but their tradition and culture. In fact many Native Americans had wars with each other. Alot of Native Americans had language barriers because they spoke differently in various dialects. This disadvantage caused great suffering for their survival as whole people who were originally there at first. The British then later converting to americans greatly divided and conquered the entire continent of the northern hemisphere, which is middle part of north America. The Young nation soonly to become the united states isolated themselves and their problems in order to create their own nation. Isolation soonly started once the United states reached from coast to coast having all in their hands to control. Manifest Destiny
Then humans showed up. Today, the Sahara Desert is defined by undulating sand dunes, unforgiving sun, and oppressive heat. But just 10,000 years ago, it was lush and verdant.
