Felipe Sandoval (defendant) was charged under federal law with introducing alcohol onto the lands of the Pueblo Indians in the State of New Mexico. The district court dismissed the indictment against Sandoval. The district court held that the federal government lacked jurisdiction to enforce federal law on Pueblo Indian land and that the exercise of federal jurisdiction would conflict with the police powers of the State of New Mexico. The federal government appealed, pointing out that, upon admission to the United States, New Mexico had agreed that Pueblo Indian land would be treated as Indian land subject to federal law. The United States Supreme Court granted certiorari.