In 1924.
https://en.wikipedia.org/wiki/Indian_Citizenship_Act
As with all indigenous peoples over run by Europeans, the return of their human rights is still in question though they are allowed a small something about two or three times a century... over the last six centuries. We're still putting kids in cages.
It's still happening in most of the former colonial territories. The bigotry in Australia is much nastier than what we have here, which is already a pretty low low.
One problem in this case is that many indigenous peoples cover areas that often straddle poitical boundaries thta have been established after they already had their own and many were moved elsewhere.
Most of the arguments over sovereignty, citizenship, and locational birthright are dicey at best. I know of tribes that are from the lakes region but they have had issues with Canada and the US over going from one part of their reservation to the other because it straddles the border. One of my in-laws has the same issue with US/Mexico who is a full blooded Native American. Not sure when that one gets solved either. They may be from one homeland that is made up of several countries and sometimes states in the minds of others. That's how I see this situation.