Those puzzled by the ease with which contemporary progressive political movements have turned against liberal values such as free speech will find much material for reflection in Leonard’s lucid intellectual history of early twentieth-century progressivism. From the beginning, the Progressive movement saw itself as a rival of nineteenth-century liberalism, not simply in the sphere of economics (replacing laissez faire with a more regulated economy) but also in the arena of individual liberties and rights. The advances of the late nineteenth century had led many intellectuals to believe that educated experts could make better decisions than the uninformed could make for themselves. Progressives aimed at social, economic, and natural engineering on a vast scale. Immigration restrictions, prohibition, and forced sterilization of “undesirable” members of the gene pool would reshape the lower classes; meanwhile, economic regulation would maintain fairness by limiting the power of corporate trusts. Leonard’s commendable book illuminates one phase in the centuries-long American struggle between the quest for liberal values and the impulse to build a godly commonwealth on the back of a strong state.