Later Amendments

The Constitution has been amended twenty-seven times since 1791. The amendment process is deliberately difficult — two-thirds of both houses of Congress, then ratification by three-quarters of the states — and the result is that the amendments cluster around periods of major political crisis rather than accumulating continuously. The eleventh and twelfth came quickly (1795, 1804), addressing sovereign immunity and the Electoral College. Then a gap of sixty years.

The Civil War amendments are the second founding. The Thirteenth Amendment (1865) abolished slavery and involuntary servitude except as punishment for crime — the resolution of the Three-Fifths Compromise's original sin, through four years of war and six hundred thousand dead. The Fourteenth Amendment (1868) established birthright citizenship, equal protection of the laws, and due process as federal constitutional guarantees applying to the states — the amendment that has done the most work in twentieth-century constitutional jurisprudence. The Fifteenth Amendment (1870) prohibited denying the right to vote on account of race, color, or previous condition of servitude. Together the three amendments carry the Declaration's philosophical premises into the territory the framers had refused to take them.

The Progressive Era produced four amendments in close succession: the Sixteenth (1913, authorizing the federal income tax), the Seventeenth (1913, providing for direct election of senators rather than by state legislatures), the Eighteenth (1919, Prohibition), and the Nineteenth (1920, extending the vote to women). The Twenty-First Amendment (1933) repealed the Eighteenth — the only time the Constitution has been amended to undo an amendment. Later amendments addressed presidential succession (Twenty-Second, limiting presidents to two terms; Twenty-Fifth, governing succession on disability), the voting age (Twenty-Sixth, lowering it to eighteen), and congressional pay (Twenty-Seventh, preventing pay increases from taking effect until after an intervening election).