A century ago, horses were ubiquitous in America. They plowed the fields, transported people and goods within and between cities and herded livestock. About a million of them were shipped overseas to serve in World War I. Equine and related industries employed vast numbers of stable workers, farriers, wainwrights, harness makers and teamsters. Cities were ringed with fodder-producing farmland, and five-story stables occupied prime real estate in Manhattan. Then, in just a few decades, the horses vanished in a wave of emerging technologies. At the same time, those technologies fostered unprecedented economic growth, and with it a culture of recreation and leisure that opened a new place for the horse as an athletic teammate and social companion.