Final answer:
African Americans in the North were subjected to de facto segregation, which is separation due to practices and social norms, rather than de jure segregation, or legal mandate, which was the case in the South with Jim Crow laws.
Step-by-step explanation:
Unlike those in the South, African Americans in the North were subjected to de facto segregation. De facto segregation refers to segregation that occurs due to customary practices and social norms rather than by codified laws or legal mandate. In contrast, the South had de jure segregation, which was enforced by laws such as the Jim Crow laws. These laws mandated the separation of races in all facets of public life, including schools, transportation, and other public facilities, under the 'separate but equal' doctrine affirmed by the Supreme Court's Plessy v. Ferguson decision. While de jure segregation was eventually challenged and found unconstitutional, particularly with the Brown v. Board of Education case, de facto segregation in the North persisted through social and economic practices, even without specific laws mandating segregation.