In the 1901 case of Chin Bak Kan v. United States, the U.S Supreme Court ruled on a matter concerning immigration law and its application to Chinese immigrants. The petitioner, Chin Bak Kan, was denied entry into the United States based on an interpretation of Section Six of the Act which Congress passed in September 1894 that required Chinese laborers seeking re-entry into America to possess certificates verifying their previous residence status. Despite having lived in America for several years prior to visiting China temporarily, he did not have such certification due to his departure from America before this law's enactment. Upon return from China after this act became effective, he was refused admission at port by immigration officials who cited non-compliance with new regulations as reason for denial. Chin Bak Kan appealed against this decision arguing that it violated treaty agreements between China and USA guaranteeing freedom of movement for Chinese residents within American borders; however his appeal was unsuccessful both at district court level and subsequently when escalated up to Supreme Court level where justices upheld earlier rulings stating that congressional legislation superseded any conflicting provisions within existing treaties thus validating actions taken by immigration officers.

In the dissenting opinion for Chin Bak Kan v. United States, Justice Harlan argued that the majority's decision to uphold a law excluding Chinese immigrants from reentering the U.S. after visiting their home country was unconstitutional and violated international treaty obligations. He contended that Congress did not have unlimited power to exclude aliens and should respect existing treaties with foreign nations unless there were compelling reasons of public safety or welfare at stake. Furthermore, he believed that this law unfairly targeted Chinese immigrants based on race and nationality, which contradicted principles of equality under American law. The justice also expressed concern about potential retaliation by China against American citizens abroad due to this discriminatory policy.