One was because they had good soil for planting. forget the other two! seriously, look it up in a history book:)
The reasons as to why Americans would be patriots is that America is land of opportunity and two this is a heritage that they will leave to their next of kin.
Two reasons, the expanding population of immigrants wanted their own land for farming and much of the land in Virginia and points south was depleted of nutrients by over farming of cotton, tobacco and corn, causing many to move west for newer fertile lands.
The need for civil rights and political power.
Land and gold
frontiersmen seeking adventure and farmers and ranchers seeking land
religious freedom and the gold rush
Local tribes were relocated and conscripted into forced labor on the mission.
The coloney was the base of fur trade with the Native Americans
Oregon Trail & Santa Fe Trail
Settlers began Western expansion because there was limitless amounts of cheap, undeveloped land. Also, travel to the West was made easier by various canal systems and railroads.
The plains tribes which included the Sioux, Blackfoot just to name two.