False they were called the 49ers
Answer:
The westward expansion affected the Native American tribes because the colonists were taking over their land and driving them out which would lead to the trail of tears where the Native Americans either died,got sick, or suffered from loved ones dying.
Answer:Mining gold and silver brought a large amount of people west. The opportunity to get rich quick was an enticement for many. There was untouched ground to the west ready for harvest.
Freedom from a tyrannical monarchy and the opportunity to start a new life in a land that had not yet had a government established leaving the door open to start their own government to be run how they desired.