What does "separate but equal" refer to?

The phrase "separate but equal" refers to a legal doctrine that justified racial segregation, particularly evident in the context of American history. This doctrine was established by the Supreme Court case Plessy v. Ferguson in 1896. The ruling upheld the constitutionality of racial segregation under the guise that segregated facilities for black and white individuals were intended to be equal. However, in practice, this led to systemic inequalities, as the facilities and services provided to African Americans were generally inferior compared to those available to white individuals.

This legal rationale perpetuated discrimination and was a cornerstone of Jim Crow laws in the Southern United States, legitimizing numerous discriminatory practices for decades until it was ultimately overturned by later Supreme Court decisions, such as Brown v. Board of Education in 1954, which declared that "separate educational facilities are inherently unequal."

In contrast, the other choices focus on different concepts that do not relate to the historical framework or implications of the "separate but equal" doctrine, making them irrelevant in the context of this question.