John Elk, a Winnebago Indian, was born on an Indian reservation and later resided with whites on the non-reservation US territory in Omaha, Nebraska, where he renounced his former tribal allegiance and claimed citizenship by virtue of the Citizenship Clause. The case came about after Elk tried to register to vote on April 5, 1880 and was denied by Charles Wilkins, the named defendant, who was registrar of voters of the Fifth ward of the City of Omaha.
The court decided that even though Elk was born in the United States, he was not a citizen because he owed allegiance to his tribe when he was born rather than to the U.S. and therefore was not subject to the jurisdiction of the United States when he was born. The decision was later reversed with the Indian Citizenship Act of 1924.
The question then was whether an Indian born a member of one of the Indian tribes within the United States is, merely by reason of his or her birth within the United States and of his afterward voluntarily separating him or herself from the tribe and taking up residence among white citizens, a citizen of the United States within the meaning of the first section of the Fourteenth Amendment of the Constitution.
Under the Constitution, Congress had and exercised the power to regulate commerce with the Indian tribes, and the members thereof, within or without the boundaries of one of the states of the Union. The "Indian tribes, being within the territorial limits of the United States, were not, strictly speaking, foreign states"; but "they were alien nations, distinct political communities", with whom the United States dealt with through treaties and acts of Congress. The members of those tribes owed immediate allegiance to their several tribes, and were not part of the people of the United States.
Thus, born a member of an Indian tribe, even on American soil, Elk could not meet the allegiance test of the jurisdictional phrase because he “owed immediate allegiance to” his tribe, a vassal or quasi-nation, not to the United States. The Court held Elk was not "subject to the jurisdiction" of the United States at birth. "The evident meaning of these last words is, not merely subject in some respect or degree to the jurisdiction of the United States, but completely subject to their political jurisdiction, and owing them direct and immediate allegiance."