Plessy v. Ferguson (1896) was the seminal post-Reconstruction Supreme Court decision that judicially validated state-sponsored segregation in public facilities by creating and endorsing the “separate but equal” doctrine as satisfying the Constitutional requirements provided in the Fourteenth Amendment to the United States Constitution. The decision was 7-1 with one abstention by Justice John Marshall Harlen, whose lone dissent earned him the nickname, “the Great Dissenter.” 

Background

After the Compromise of 1877 led to the withdrawal of federal troops from the South, Democrats consolidated control of state legislatures throughout the region, effectively marking the end of Reconstruction. In the absence of federal assistance, southern Black people saw the promise of equality under the law embodied by the 13th Amendment, 14th Amendment, and 15th Amendment to the Constitution receding quickly, and a return to disenfranchisement and other disadvantages as white supremacy reasserted itself across the South.

In 1890, the state of Louisiana passed the Separate Car Act, which required separate accommodations for blacks and whites on railroads, including different railway cars. Concerned, a group of prominent black, creole people of color, and white creole New Orleans residents formed the Comité des Citoyens (Committee of Citizens) dedicated to repealing the law or fighting its effect. The group persuaded Homer Plessy, a man of mixed race to participate in an orchestrated test case. Plessy was born a free man and was a fair-skinned man of color. However, under Louisiana law, he was classified as black and thus required to sit in the "colored" car.

To ensure that Plessy would be arrested, the Comité des Citoyens hired a private detective with arrest powers to detain Plessy. The detective’s task was to ensure that Plessy was charged for violating the Separate Car Act instead of being charged with vagrancy or some other offense. After Plessy took a seat in the whites-only railway car, he was asked to vacate it and sit in the blacks-only car. Plessy refused and was arrested immediately by the detective. As planned, the train was stopped, and Plessy was taken off the train. 

Plessey’s conviction was sustained through the state courts and ultimately found its way to the United States Supreme Court. Plessy argued that the Louisiana Separate Car Act violated both the Thirteenth Amendment, abolishing slavery, and the Fourteenth Amendment denying Blacks the right to Life, Liberty, and Pursuit of Happiness by making them inferior to whites. 

The majority of the Court rejected the view that the Louisiana law implied any inferiority of blacks. Instead, it contended that the law separated the two races as a matter of public policy. In effect, The Plessy decision legitimized segregation practices that had begun earlier in the South and provided a legal framework for additional segregation laws throughout the rest of the nation. It also legitimized laws in the North requiring "racial" segregation, such as in the Boston school segregation case noted by Justice Brown in his majority opinion.

Impact 

The effect of the Plessy ruling was immediate; there were already significant differences in funding for the segregated school system, which continued into the 20th century; states consistently underfunded black schools, providing them with substandard buildings, textbooks, and supplies. States that had successfully integrated their society elements abruptly adopted oppressive legislation that erased reconstruction era efforts. 

Jim Crow laws and practices spread northward in response to the second wave of African-American migration from the South to northern and midwestern cities. Some established de jure segregated educational facilities, separate public institutions such as hotels and restaurants, separate beaches, and other public facilities, and restrictions on interracial marriage. Still, in other cases, segregation in the North was related to unstated practices and operated on a de facto basis, although not by law, among numerous different facets of daily life.

Last but not least, state legislatures in the South disenfranchised blacks and many poor whites by rejecting them for voter registration and voting. They accomplished this by requiring proof of land ownership or administering literacy tests to people of color. African-American community leaders, who had achieved brief political success during the Reconstruction era and even into the 1880s, lost gains made when their voters were excluded from the political system. 

It wasn’t until Brown v. Board of Education (1954) that this “separate but equal” doctrine was challenged and abolished.