Homer Plessy, a mixed-race man from New Orleans, was arrested for refusing to leave his seat in the "whites-only" car of a train; he lost the resulting court case, Plessy v. Ferguson.

Homer Adolph Plessy was an American shoemaker and activist who was the plaintiff in the United States Supreme Court decision Plessy v. Ferguson. He staged an act of civil disobedience to challenge one of Louisiana's racial segregation laws and bring a test case to force the U.S. Supreme Court to rule on the constitutionality of segregation laws. The Court decided against Plessy. The resulting "separate but equal" legal doctrine determined that state-mandated segregation did not violate the Fourteenth Amendment to the United States Constitution as long as the facilities provided for both black and white people were putatively "equal". The legal precedent set by Plessy v. Ferguson lasted into the mid-20th century, until a series of landmark Supreme Court decisions concerning segregation, beginning with Brown v. Board of Education in 1954.