The entire Native American population got voting rights along with all US citizens with the Voting Rights Act of 1965. Prior to that, individual states gave voting rights to certain tribes. There was a famous case in the late 40's (48?) that gave the Navajo rights in Arizona. Several states followed suit but it's been too long and my memory is too fuzzy for anymore details. I think you can probably find out on the net, but the answer to "when for all" is 1965 for sure.

Spaw