Final answer:
The case of Plessy v. Ferguson made it to the Supreme Court through an appeal by Plessy's lawyers after a state court decision. The Supreme Court agreed to hear the case and ultimately ruled against Plessy, establishing the concept that segregation was legal as long as separate facilities for whites and blacks were equal.
Step-by-step explanation:
In 1896, the case of Plessy v. Ferguson made it to the Supreme Court through an appeal by Plessy's lawyers after a state court decision. They appealed the decision on the grounds that the Louisiana law requiring segregation on public railroads violated the principle of equal protection under the law in the Fourteenth Amendment. The Supreme Court agreed to hear the case and ultimately ruled against Plessy, establishing the concept that segregation was legal as long as separate facilities for whites and blacks were equal.