Answer:
It brought them diseases such as small pox, measles chicken pox etc.
Answer:
A. The Indian Removal Act
Answer:
What negative impact did it have? Provided flood control, hydroelectric power, conservation, recreational facilities; coal burning caused environmental pollution.
So all the power isnt in one persons hands, and because if checks and balances werent here one person would hold all the power which would be bad :)
Maybe you could write about how the Bill of Rights affects trials in America so much with the 4th,5th,6th,7th, and 8th amendment.