The Trail of Tears was one event among many others. The American Indian wars and Manifest Destiny saw the Native population decline from 600,000 to 250,000.
But the US doesn't get to pretend it doesn't inherit the genocide it was founded on! Killings that happened before 1776 were carried out by prominent colonial generals like George Washington before the Founding, and their forefathers like John Washington who the Iroquois named "devourer of villages".
Let's not forget the intentional hunting of buffalo to extinction in the wild by the US army, intended to starve the plains Natives to death or force them to flee. The US also had boarding schools like Canada, where they'd kidnap native children and brainwash them to be good little Christians that can't even speak their native languages.
The fact that you think the genocide was limited to a single event like the Trail of Tears is disturbing.