In the reality of U.S. history, classical liberalism had two moments of special prominence: the era in which the federal Constitution was adopted and the subsequent early national period, and then in the decades following the Civil War. The latter period was especially significant, because it was a time of economic “takeoff” in which lightly regulated industries grew enormously, contributing to a significant leap in economic growth along with a surge in wages for many.

But of course this was also the era of the robber barons, the great monopolies and trusts, and the rise of the People’s Party, the original populists, who took a stand against the inequality, dislocations, and social and communal costs of unrestrained economic dynamism and creative destruction. From out of that protest grew the Progressive movement, the New Deal, and the rest of modern liberalism — which is best understood as an absolutely necessary corrective to the injustices produced by the freewheeling churn of classical liberalism.

That’s why classical liberalism is and always will be both necessary and radically insufficient to serve as the governing philosophy of a free and equal democratic society. Such a society needs and depends on economic growth. But that very dependence invariably leads it to downplay the tendency of private entities (big business; wealthy elites; slave owners; racial majorities) to acquire and wield the kind of power formerly wielded only by states.