On May 18, 1896, the U.S. Supreme Court released a 7-1 decision in Plessy v. Ferguson, a case challenging racial segregation laws in Louisiana, holding that state-mandated segregation in intrastate travel was constitutional as long as the separate accommodations were equal.

The Court had heard arguments a month earlier on April 13. Homer Plessy, a Black man who had been arrested for boarding a "white only" passenger car, argued that the state segregation law violated the Thirteenth and Fourteenth Amendments, which abolished slavery and established equal protection of the laws.

In 1890, Louisiana passed the Separate Car Act, requiring railroad companies to provide separate passenger cars for Black and white travelers. The Comite des Citoyens (“Committee of Citizens”), a New Orleans group of Black men who employed civil disobedience to challenge segregation laws, wanted to challenge the law's constitutionality. When Mr. Plessy—a Black man—was arrested for boarding a “white only” passenger car, the committee helped him to appeal, and the case eventually reached the U.S. Supreme Court.

On May 18, Justice Henry Brown wrote the majority opinion, which held that the Louisiana law did not violate the Thirteenth or Fourteenth Amendments because it did not interfere with an individual’s personal freedom or liberties. He claimed the Court could uphold the notion that all people are equal before the law in political and civil rights but could not override social inferiority based upon the distinction of race.

Justice John Marshall Harlan dissented, writing that the Louisiana law was in direct violation of the Thirteenth and Fourteenth Amendments' promise of protection of all civil rights related to freedom and citizenship. Justice Harlan specified that the law was a blatant attempt to infringe upon the civil rights of African Americans and that the Court inappropriately yielded to public sentiment at the expense of constitutional safeguards. He predicted the Court’s decision would lead to racial confrontation.

Plessy v. Ferguson legally sanctioned racial segregation by establishing the “separate but equal” doctrine as national law. Public services and accommodations were segregated for decades, until the Court’s Brown v. Board of Education decision in 1954 overruled the application of “separate but equal” in public education and the Civil Rights Act of 1964 prohibited it in public accommodations.