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.
The Articles of Confederation (Simplified) Approved by all 13 states between 1777 and 1781. The Articles of Confederation has 13 sections called articles.
8. I believe that witnessing the man next to him die was the worst negative. Harold went into war excited but watching someone die right next to him showed him the war is no happy place.