When Alexis de Tocqueville travelled to the United States in 1831 and 1832 he was struck by the energy of American democracy. Americans, he observed, were continually engaged in governing themselves and that engagement spilled over into the economy and society generating an uncommon vitality. A primary reason for this energy and vitality was America’s decentralized political system. Through the Constitution’s system of federalism power was divided between national and subnational governments allowing citizens to decide local questions for themselves. This decentralization he contended draws individuals out of private life and compels them to civic engagement.
Federalism is one of the great innovations of the American Founders. Before the American Constitution, governments were either national with all power concentrated in a central government or confederal with individual governments retaining sovereignty and voluntarily cooperating for limited purposes, like the Articles of Confederation that preceded the Constitution. The idea that power over individuals could be shared between a national government and multiple state governments was new. The system created by the Constitution was so new that that the authors did not have a word for it so they changed the meaning of the old word “federal”. At the time federal simply meant confederation.