Separate but equal is a legal doctrine that originated from the U.S. Supreme Court ruling in Plessy v. Ferguson (1896), which upheld racial segregation under the premise that separate facilities for different races could be considered equal. This doctrine became a cornerstone of Jim Crow laws, leading to widespread discrimination and the establishment of inferior services for African Americans compared to their white counterparts. It essentially legitimized the racial divide in public spaces and services, creating an environment of systemic inequality.