Law and legislationAfrican AmericansDiscrimination in employmentDiscrimination in employment, law and legislationHistoryAfrican americans, employmentAfrican americans, history, to 1863Afro-AmericansCasesCausesCivil rightsDiscrimination in employment, united statesDiscrimination in housingEmploymentLabor laws and legislationSlaverySlavery, united states, historyUnited states, history, revolution, 1775-1783, causes