In the Barker v. Harvey case of 1900, the U.S Supreme Court ruled on a dispute over land in Oklahoma that was claimed by both the Choctaw Nation and individual American citizens. The court decided in favor of the Choctaw Nation, affirming their title to certain lands under treaties made with them by the United States government. The decision clarified that these treaties were still valid despite subsequent legislation or proclamations which seemed to suggest otherwise. It also noted that while Congress had power over Indian affairs, it could not unilaterally abrogate treaty rights without clear intent to do so. This ruling reinforced tribal sovereignty and upheld treaty rights as binding federal law.

In the dissenting opinion for Barker v. Harvey, Justice Harlan argued that the majority's decision was inconsistent with previous rulings of the Supreme Court regarding territorial acquisitions. He contended that when a territory is acquired by the United States, it becomes part of U.S., and its inhabitants become citizens entitled to constitutional protections unless Congress explicitly states otherwise. In this case, he believed that Colorado had been incorporated into U.S., making its residents full-fledged American citizens who should not be denied their rights under any circumstances. Therefore, according to him, denying Mr. Barker his mining claim on public lands in Colorado based on an 1864 law which stated only U.S citizens could make such claims was unconstitutional as it violated his rights as a citizen.