The U.S. Supreme Court upheld the decision of the Louisiana courts, by a 7–1 vote, against Homer Plessy, a part–African American man who was arrested under the state’s Separate Car Act after boarding a train car reserved for white passengers. Associate Justice John Marshall Harlan, the lone dissenter, argued that segregation laws violated the Thirteenth and Fourteenth amendments to the U.S. Constitution and were designed not to create equality but to mark African Americans as inferior. Plessy and his legal team’s attempt to have the Separate Car Act struck down on constitutional grounds failed.

The decision gave legal and constitutional sanction to laws designed to achieve racial segregation for decades afterward, by designating separate and supposedly equal public facilities and services for African Americans and white people. State and local governments in the South continued to pass segregationist Jim Crow laws until 1954, when the “separate but equal” doctrine was challenged and overturned through the Supreme Court’s decision in Brown v. Board of Education.