If you are referring to colonization and how that hurt the Native American population... that is not the same of the current conditions.
America is a country of immigrants. Yet, every group of immigrants is angry when a new group comes in. Though, once the new groups come and assimilate and work and pay taxes and create a great culture... America is better for it.
Your argument is a tautology. "America is better for it," is true, because America is always being redefined as it changes. "The groups who comprised America a 100 years ago" are perhaps not better for it. It is a trivial thing to point out that AmerIndians are quite a bit better off in every measurable aspect of their lives than 500 years ago. Every has improved but the real estate/sovereignty situation.
America is a country of immigrants. Yet, every group of immigrants is angry when a new group comes in. Though, once the new groups come and assimilate and work and pay taxes and create a great culture... America is better for it.