Why was Plessy v. Ferguson a negative ruling for African Americans?

Plessy v. Ferguson was a negative ruling for African Americans because it upheld the constitutionality of racial segregation under the "separate but equal" doctrine. This decision legitimized state laws that enforced racial discrimination, effectively institutionalizing Jim Crow laws across the South. As a result, it perpetuated social and economic inequalities, denying African Americans equal access to public facilities and services. The ruling set a precedent that hindered civil rights advancements for decades.