In this article, Michael Zuckert sets out to provide the context, content, and implications of the Post-Civil War amendments (the 13th, 14th, and 15th). The 13th amendment was adopted immediately after the Civil War and served the simple task of forbidding slavery. However, discrimination against freed slaves still continued through laws called Black Codes. In response to these Black Codes, the Civil Rights Act of 1866 and the 14th amendment were established. Among its various functions, the 14th amendment defines who citizens are, prohibits state and federal abridgment of rights without due process of law, and requires states to give equal protection of the laws to all persons. The due process and equal protection clauses, heavily influenced by Locke’s natural rights and social contract philosophy, reflect the two tasks of government, both negative and positive: not to invade citizens’ rights, and to protect those rights from being violated. As a standard, equal protection provides the states and federal government with a clear criterion by which to protect citizens’ rights. In contrast to the 13th and 14th amendments, the 15th amendment protects not a natural, but a political right: the right to vote. Although it forbids the denial of voting rights on the basis of race, it leaves open the possibility of that denial on other bases.