Of the reform periods, the Progressive Era holds the clearest parallels to ours. In the 1890s, inequality, partisanship and discontent were all sky-high. The depression of 1893-97 shattered faith that a growing industrial economy would lift all boats. New leviathan railroad and public-utility corporations seemed imposingly powerful, and partisan politics seemed thoroughly corrupted by them. Mass immigration was changing the face of the nation.

As public dissatisfaction built, and pressure grew from multiple directions, the political system eventually responded, led by a new generation of reform-oriented activists and politicians. New forms of participatory democracy — the primary, direct elections for the Senate, the initiative and the referendum — reshaped a political system that seemed to privilege the few over the many.

Women achieved the right to vote, first in cities and states, then finally nationwide in 1920. New regulatory agencies wrestled with the size and scope of giant corporate enterprises, cutting some down to size, putting stricter boundaries on others. But even as late as 1902, it was far from obvious that the years ahead would bring so much change.