Final answer:
Jim Crow laws were used in the southern United States to enforce racial segregation in public facilities and accommodations, backed by the 'separate but equal' doctrine established by the Supreme Court in Plessy v. Ferguson.
Step-by-step explanation:
Jim Crow laws were state laws that were enforced primarily in the southern United States from the late 1800s until 1965. These laws institutionalized racial discrimination and segregation, mandating the separation of races in all aspects of public life, including schools, transportation, and healthcare facilities. African Americans faced 'separate but equal' treatment, however, the facilities and accommodations provided to them were typically far inferior to those available to White Americans. The Plessy v. Ferguson Supreme Court case in 1896, which upheld the doctrine that separate facilities for blacks and whites were constitutional under the 'separate but equal' principle, was a significant legal backing for these laws. It was not until the Brown v. Board of Education case in 1954 that the Supreme Court began to reverse this doctrine, setting the stage for desegregation.