A legal study that investigates how American constitutions, statutes, and judicial decisions have created and enforced distinctions among racial groups, especially focusing on the legal status of Black Americans after emancipation. It defines what counts as a race-based legal distinction, traces laws labeled as black codes and later statutes, and examines how law treated marriage, intermarriage, civil rights and accommodations, education, public transport, labor and criminal regulations. The author compares federal and state measures, summarizes key court rulings, and assesses where statutory distinctions produce formal separation or unequal treatment, presenting sources and notes for readers interested in legal authority.