How do you think Jim Crow laws were allowed to stand, when they clearly violated the 14th Amendment?

The Supreme Court's narrow interpretation of the Fourteenth Amendment cleared the way for southern states to impose new, discriminatory legal regimes based on segregationist principles. In 1877, the Union Army ended its military occupation of the defeated old Confederacy; with neither northern soldiers nor federal judges willing to intervene on their behalf, African-Americans soon found themselves under the thumb of Jim Crow. Radical Reconstruction had ended in total failure, its ambitious vision of colorblind democracy relegated to the ash-heap of history for nearly 100 years. Upon the ruins of Reconstruction, southerners quickly built a new social and legal system designed to ensure white supremacy.

Through the 1870s and 1880s, southern states enacted a series of laws to compel the segregation of white and black citizens in education, public accommodations, public transport, and even sexual relations. In 1890, the State of Louisiana passed one of those laws—a new statute requiring all railroads to provide separate cars for each race, and banning blacks from riding in cars reserved for whites (or vice versa).