Explanation
in 1870, after the 14th Amendment’s ratification, U.S. Census figures showed that just 8 percent of American Indians were classified as “taxed” and eligible to become citizens. The estimated American Indian population in the 1870 census was larger the population of five states and 10 territories—with 92 percent of those American Indians ineligible to be citizens.
The troublesome definition of “taxed Indians” and the price of citizenship imposed on American Indians (loss of communal lands and cultural identify) dated back to another well-known Supreme Court Chief Justice, John Marshall. And it took the Great Dissenter, Justice John Marshall Harlan, to put the question of American Indians birthright citizenship into context, in the form of great dissent.
In what were later known as the Marshall Trilogy rulings, the Chief Justice established the precedents for how the United States legal system would deal with political and social rights for American Indians who lived in the territorial boundaries of the United States.
Marshall wrote in Cherokee Nation v. Georgia in 1831 that the Cherokees didn’t have legal standing to prevent the state of Georgia from seizing its lands.
“It may well be doubted whether those tribes which reside within the acknowledged boundaries of the United States can, with strict accuracy, be denominated foreign nations,” Marshall said about claims that the Cherokee were an independent state.
“They may, more correctly, perhaps, be denominated domestic dependent nations. They occupy a territory to which we assert a title independent of their will, which must take effect in point of possession when their right of possession ceases. Meanwhile they are in a state of pupilage. Their relation to the United States resembles that of a ward to his guardian,” he concluded.
The case didn’t preclude attempts by the federal government already underway in the 1830s, as part of an intense drive to acquire land occupied by American Indians east of the Mississippi, to grant citizenship to tribes using treaties and statutes.
Individuals were left their tribes to live outside of tribal areas fell into a different category. The Constitution in Article I said that “Indians not taxed” couldn’t be counted in the voting population of states (and slaves were counted as three-fifths of a person).
In 2000, Earl M. Maltz, Distinguished Professor of Law, Rutgers-Camden, explained one problem “taxed Indians” soon faced in an analysis of the 14th Amendment and citizenship.
“Native Americans who remained within the tribal structure were not to be considered at all in determining the number of representatives to which a state was entitled.  By contrast, those who joined white society were counted fully in the basis of representation,” Maltz said.
“In general, however, even these Native Americans were not considered the full political equals of white people. Indeed, Native Americans who left their tribal communities were not even eligible for naturalization under the general naturalization statute, which allowed only white people to become naturalized citizens,” he said.
Taney confirmed in the Dred Scott decision the federal government could grant citizenship to whole Indian tribes or nations, and the issue came up a decade later as Congress considered the Civil Rights Act and the 14th Amendment.
In January 1866, the Senate started debate of the Civil Rights Act when Senator Lyman Trumbull of Illinois introduced the bill. Members of both parties were concerned that the bill’s broad language would confer citizenship on all American Indians.
Trumbull assured the senators that the bill would only grant citizenship to American Indians "who are domesticated and pay taxes and live in civilized society" and were therefore "incorporated into the United States."
However, the act’s language was modified to limit language about birthright citizenship “Indians not taxed” to appease opposition.
When Justice John Marshall Harlan looked at these debates as he wrote his dissent in Elk v. Wilkins in 1884, the intent seemed obvious.
“It would seem manifest, from this brief review of the history of the act of 1866, that one purpose of that legislation was to confer national citizenship upon a part of the Indian race in this country—such of them, at least, as resided in one of the states or territories, and were subject to taxation and other public burdens,” Harlan said.
Harlan also said the 14th Amendment’s intention was equally clear in this area, as an extension of the Civil Rights Act of 1866.
“[It} was intended to grant, national citizenship to every person of the Indian race in this country who was unconnected with any tribe, and who resided, in good faith, outside of Indian reservations and within one of the states or territories of the Union,” he said.
hope this helps :)
