The 1896 supreme court ruling that approved "separate but equal" accommodations for blacks and whites as a reasonable use of state power was

It was Plessy v. Ferguson. Plessy v. Ferguson upheld state racial segregation laws for public facilities under the doctrine of "separate but equal" and was a landmark constitutional law case of the 1896 US Supreme Court. It was the result of 1892 incident where Homer Plessy, an African-American train passenger  refused to sit in a Jim Crow car.