How did southern states use the courts in 1896 ruling to extent segregation?

In the 1896 ruling of Plessy v. Ferguson, the U.S. Supreme Court upheld the constitutionality of racial segregation under the "separate but equal" doctrine. Southern states seized this ruling as a legal precedent to justify and expand segregationist laws, enacting Jim Crow laws that institutionalized racial discrimination in public facilities, education, and transportation. The decision provided a legal framework that allowed states to maintain and legitimize systemic racism, leading to widespread disenfranchisement and social inequality for African Americans.