Mainly from Europe more specifically Germany ,Ireland, England and France due to various problems such as crop failure. They have also immigrated because of Christopher Columbus's voyages of the new world.
Explanation:
I believe they used the phrase "Manifest Destiny." In other words, they believed that it was their destiny to have the land and to build upon it.
The damage outweighed the benefits to the American people because it meant they got to "have more." In other words, more money.
The government could have made an agreement with the natives and possibly allowed them to continue living on the land, perhaps, that would have caused less wars or battles in the end.
It was mainly around the years of 1630 I believe.
They were called Roundheads