The Center Cannot Hold by Harry Turtledove

In this spectacular, thought-provoking epic of alternate history, Harry Turtledove has created an unparalleled vision of social upheaval, war, and cutthroat politics in a world very much like our own—but with dramatic differences. It is 1924—a time of rebuilding, from the slow reconstruction of Washington's most honored monuments to the reclamation of devastated cities in Europe and Canada. In the United States, the Socialist Party, led by Hosea Blackford, battles Calvin Coolidge to hold on to the Powell House in Philadelphia. And it seems as if the Socialists can do no wrong, for the stock market soars and America enjoys prosperity unknown in a half century. But as old names like Custer and Roosevelt fade into history, a new generation faces new uncertainties.