What principle does Plessy v. Ferguson establish regarding segregation?

The case of Plessy v. Ferguson, decided by the U.S. Supreme Court in 1896, established the legal principle that segregation is permissible as long as the separate facilities provided for different races are deemed equal. This ruling provided a constitutional justification for the continued practice of racial segregation across various aspects of public life, including transportation, education, and accommodations.

This principle, often summed up by the phrase "separate but equal," led to widespread implementation of segregation laws, known as Jim Crow laws, throughout the Southern United States. The ruling held significant implications for civil rights, as it effectively legitimized discriminatory practices, asserting that as long as facilities such as schools and public restrooms were of equal quality, they could be segregated by race without violating the Fourteenth Amendment's Equal Protection Clause.

The other options do not accurately reflect the ruling established in Plessy v. Ferguson. For instance, the claim that segregation is illegal under any circumstances contradicts the ruling itself, while the assertion that segregation must be abolished immediately misrepresents the court's decision to allow it under certain conditions. Similarly, limiting segregation to public facilities does not encompass the broader implications of the ruling that affected various public and private entities.