Final answer:
Jim Crow Laws enforced racial segregation and inequality, disenfranchising Black Americans and creating separate, inferior public facilities, contrary to the promises of the Fourteenth Amendment.
Step-by-step explanation:
Jim Crow Laws negatively impacted Black Americans by enforcing racial segregation, leading to discrimination and inequality. These laws mandated the separation of races in all aspects of life including schools, public buildings, parks, hospitals, transportation, and even water fountains, with facilities for African Americans routinely being inferior.
The doctrine of 'separate but equal,' legitimized by the Plessy v. Ferguson case, gave a legal cover to these discriminatory practices. Moreover, Jim Crow Laws were responsible for disenfranchisement, preventing Black Americans not only from voting but also from serving on juries or running for public office, thereby undermining the civil and social rights promised to them by the Fourteenth Amendment.