How did the Plessy v. Ferguson case (1896) uphold Jim Crow laws? What effect did this case have on the lives (transportation, education, social implications, etc) of southern blacks?

By the courts deciding on a "separate but equal" decision, this case became the legal basis for racial segregation in the United States for the next 50 years. This was essentially slavery called by another name. The ramifications of this case are still felt to this day. African Americans were given poor healthcare,education and transportation,while their public facilities such as water fountains and libraries, were barely usable.