Final answer:
White people in the United States established Jim Crow laws through disenfranchisement of black citizens, manipulation of the legal system, and the enforcement of the "separate but equal" doctrine, which was reinforced by the Supreme Court's decision in Plessy v. Ferguson.
Step-by-step explanation:
Jim Crow Laws and Racial Segregation:
The principal means by which white people in the United States enforced Jim Crow laws on black citizens after Reconstruction was through the manipulation of the political system. With black people effectively disenfranchised, the Democratic Party's control in the South ensured that any opposition to these laws was minimized. Southern state governments passed legislation that excluded African Americans from juries, sanctioned forced labor, and implemented the "separate but equal" doctrine, mandating segregation in public spaces. Crucially, the Supreme Court's decision in Plessy v. Ferguson legitimized these practices, which were not overturned until the mid-20th century with the civil rights movement.
Other methods included the use of literacy tests and poll taxes as barriers to black voting, economic coercion, social intimidation, and outright violence—most notably by the Ku Klux Klan—to maintain white supremacy and reduce the African American population to a disenfranchised, segregated lower status. The collective impact of these laws forced African Americans into a system that was, in effect, a continuation of the restrictions and social hierarchies of slavery.