In Cincinnati City v. Morgan, the Supreme Court of the United States ruled that a municipal ordinance prohibiting African Americans from residing within city limits was unconstitutional. The court held that such an ordinance violated both the Thirteenth Amendment and Section 1 of the Fourteenth Amendment to the Constitution, which prohibited states from denying any person equal protection under law. Furthermore, it found that this type of discrimination against African Americans constituted a denial of their rights as citizens and thus could not be allowed by state or local governments. This decision set an important precedent for civil rights in America by establishing that all persons are entitled to equal protection under law regardless of race or ethnicity.

In Cincinnati City v. Morgan, the Supreme Court was asked to decide whether a city ordinance requiring African Americans to register with the police violated their rights under the Thirteenth Amendment of the United States Constitution. The majority opinion held that it did not violate any constitutional rights and upheld the ordinance as valid. However, Justice Field dissented from this decision and argued that such an ordinance was in violation of both due process and equal protection clauses found in Amendments 5 & 14 respectively. He further stated that while states have broad powers when it comes to regulating public safety, they cannot do so at expense of fundamental civil liberties or by creating distinctions based on race or color alone without sufficient justification for doing so. Thus he concluded that since there were no compelling reasons why African Americans should be singled out for registration requirements which are not imposed upon other citizens, then such an act is unconstitutional and must be struck down accordingly.