Where did different groups settle in the americas (before contact) and how and why did they move to and within the americas (after contact)?

Before Contact
Archaeologists believe that the first people to settle the Americas came here from Asia. It was said that they came walking across a land bridge between Siberia and Alaska. These Asian nomads followed herds of animals which they depended on for food. Eventually, these people settled in regions of North and South America and the Caribbean islands. Groups were small and widely scattered, and each one eventually developed a tribal identity, language, and culture all its own.Across all America Indian tribes, the culture was dictated by the climate and natural resources in the area where the people settled. Native Americans hunted local animals, ate local fruits and vegetables, and made their houses of whatever natural materials were easily found in the area. 
After Contact
The diseases brought to this continent by the Europeans including bubonic plague, chicken pox, pneumonic plague, cholera, diphtheria, influenza, measles, scarlet fever, smallpox, typhus, tuberculosis, and whooping cough.

They hold a political party