IN THE LATTER part of the nineteenth century, east coast city dwellers in the United States had difficulty repressing a sense of their own persistent cultural inferiority vis-à-vis London and Paris. At the same time a great many old-stock Americans were dismayed by the stream of immigrants coming to these shores whose diversity called the future cohesion of the Republic into question almost as seriously as the issue of slavery had done in the decades before the Civil War. In such a climate of opinion, the unabashed provinciality of Frederick Jackson Turner's (1861-1932) paper "The Significance of the Frontier in American History," delivered at a meeting of the newly founded American Historical Association in connection with the World Columbian Exposition in Chicago (1892), began within less than a decade to resound like a trumpet call, though whether it signalled advance or retreat remained profoundly ambiguous....