How did the supreme court decide the case plessy vs Ferguson?

In the 1896 case Plessy v. Ferguson, the Supreme Court upheld the constitutionality of racial segregation under the "separate but equal" doctrine. The Court ruled that state laws requiring racial segregation in public facilities did not violate the Equal Protection Clause of the 14th Amendment, as long as the separate facilities were deemed equal. This decision legitimized many forms of racial discrimination and segregation across the United States for decades.