In 1890, Louisiana passed a law called the Separate Car Act. This law said that railroad companies must provide separate but equal train cars for whites and blacks. Blacks had to sit with blacks and whites had to sit with whites. This is called segregation. Anyone who broke this law would have to pay $25 or go to jail for 20 days.

Two parties wanted to challenge the constitutionality of the Separate Car Act. A group of black citizens who raised money to overturn the law worked together with the East Louisiana Railroad Company, which sought to terminate the Act largely for monetary reasons. They chose a 30-year-old shoemaker named Homer Plessy, a citizen of the United States who was one-eighth black and a resident of the state of Louisiana. On June 7, 1892, Plessy purchased a first-class passage from New Orleans to Covington, Louisiana and sat in the railroad car for "White" passengers. The railroad officials knew Plessy was coming and arrested him for violating the Separate Car Act. Well known advocate for black rights Albion Tourgee, a white lawyer, agreed to argue the case for free.

Plessy argued in court that the Separate Car Act violated the 13th and 14th Amendments to the Constitution. The 13th Amendment banned slavery and the 14th Amendment requires that the government treat people equally. John Howard Ferguson, the judge hearing the case, had stated in a previous court decision that the Separate Car Act was unconstitutional if applied to trains running outside of Louisiana. In this case, however, he declared that the law was constitutional for trains running within the state and found Plessy guilty.

Plessy appealed the case to the Louisiana State Supreme Court, which affirmed the decision that the Louisiana law was constitutional. Plessy then took his case, Plessy v. Ferguson, to the Supreme Court of the United States, the highest court in the country. Judge John Howard Ferguson was named in the case because he had been named in the petition to the Louisiana State Supreme Court, not because he was a party to the initial lawsuit.