Introduction -- Part one. Foundations: Constitutionalism; federalism; constitutional structure -- Part two. Competitive federalism: Commerce and competition; corporations; federal common law; the fiscal constitution -- Part three. Transformation: Constitutional inversion; commerce, cartels, and concurrent powers; Erie's federalism; fiscal federalism revisited -- Part four. Our federalism: Federalism after the New Deal: rights, revenues, and regulation; from experiments to exploitation; the Supreme Court's federalism -- Part five. "Our federalism": the court, the nation, and the states; federalism among the states; conclusion: federalism at the crossroads.