The unprecedented expansion of Modem architecture throughout the wor l d must be considered one of the great events in the history of art. Within the space of the single generation, the conte m porary movement has become the dominant style of serious building not only in the United States an d Europe, where pioneers had been at work since the late nineteenth century, but also in nations such as Brazil and India, where almost no Modern architecture existed.until much later. Only the Gothic perhaps, among all the styles of the past, gained popular acceptance with anything like the speed of the Modem. And like the Gothic—which required a full seventy-five years of experimentation before it produced the cathedral of Chartres—the Modem has continually improved its structural techniques, gained in scale, and revised its aesthetics as it has attempted to meet the full range of people's civilized needs .