The major legal ruling that denied equal rights to African Americans in the United States was Plessy v. Ferguson (1896). This landmark Supreme Court case upheld the doctrine of "separate but equal," legitimizing state laws that enforced racial segregation in public facilities. Homer Plessy, an African American man, challenged Louisiana's segregation laws by sitting in a whites-only train car. The court's decision effectively sanctioned racial discrimination and established a legal foundation for Jim Crow laws throughout the South. Plessy v. Ferguson had lasting impacts, reinforcing systemic inequalities and delaying civil rights progress until the mid-20th century when it was eventually overturned by Brown v. Board of Education in 1954.