In the 1903 case of Secundino Mendezona y Mendezona v. United States, the U.S. Supreme Court dealt with issues related to immigration and naturalization laws. The petitioner, a native of Spain who had been living in Cuba before immigrating to the U.S., was denied citizenship on grounds that he did not meet residency requirements under an 1802 law which stated that only "free white persons" could become citizens after two years' residence in America. Despite having lived in Puerto Rico (a US territory) for over two years prior to his application, it was ruled this did not satisfy the requirement as Puerto Rico wasn't considered part of America at that time according to immigration laws. The court upheld this decision stating that Congress has full authority over naturalization rules and can set different standards for territories compared to states.

In the dissenting opinion for SECUNDINO MENDEZONA Y MENDEZONA v. UNITED STATES, Justice Harlan disagreed with the majority's decision to uphold Mendezona's conviction. He argued that the court had erred in its interpretation of a treaty between Spain and America regarding extradition laws. In his view, this misinterpretation led to an unjust trial where Mendezona was not allowed to present evidence or witnesses in his defense against charges of embezzlement brought by Spanish authorities. Furthermore, he contended that it was unconstitutional for American courts to try foreign citizens under foreign law without providing them with all rights guaranteed by U.S constitution such as due process and fair trial rights.