Here. Highly recommended.
An excerpt:
Baby Veronica is, or is eligible for, enrollment as a citizen of the Cherokee Nation of Oklahoma. By the way, the Cherokee Nation isn’t like your local public library—not just anyone can join. It’s like the United States. Not everyone can join us here—the U.S. has citizenship requirements. It would be unintelligible to say that someone is 3/256 American, right? You either are or are not a citizen of a nation. The usage of blood quantum in this way by the Majority conflates Indian identity and tribal citizenship.
Turtle Talk 
It is not native people that decided to use blood quantum as a way to determine the citizenship of its members. What one has to understand is the law says blood quantum has to be met or the tribal unit has to recognize the person as native. In short if they wanted to someone with blonde hair blue eves and tracing their blood lines back to Norway could be called native by any tribe. Adoption of nonnative peoples in the past was common. In fact some of the greatest native leaders were in fact white men who chose to live as native peoples. Blue Jacket comes to mind. So arguing about blood quantum is rather foolish. Of course that argument is what is causing many so called black indians to lose their places. Its rather a foolish way to determine who is native and who is not. We are not dogs to have to carry papers to prove who and what we are but the American and Canadian governments have made it so thus pitting us once more against each other.
Blood Quantum came from Scotland when the King of England took land owned by Scots based on Blood Quantum…thus a person who was half English and half Scottish lost half their land (the Scottish half). One half of the Iroquois Confederacy possessed no Native blood but were 100% European descendants by 1767…..the tribes determined who were family, clan members and tribal members……period….aho