We have seen that the Great Lakes and the great rivers were the paths to the Mississippi basin in the days of the canoe, the bateau, and the pack-horse. The early movement of population over the trans-Mississippi plains and through the passes of the Rockies was by means of wagons along well-worn buffalo traces, which Indians had followed in the pursuit of game. Where rivers intersected these overland trails, ferries were instituted, their keepers doing a thriving business in helping upon their way fur traders, explorers, miners, and settlers. Such was the origin of Kansas City and Omaha, which naturally developed, with the rush of immigration, into great centres of distribution. In every quarter of our land, from the earliest colonial days, the frontier ferryman, with his tavern and trading house, has been a town builder. The discovery of precious metals in the hills of Colorado gave life to the mining camp of Denver, which in time became the metropolis of a wide district, to which irrigation brought a wealth more enduring than gold and silver. Portland, San Francisco, and Los Angeles are the open doors of the Pacific Coast, and their growth is thus easily accounted for. Prophecies are current of the possible commercial supremacy of these Pacific-coast towns, as a consequence of our new interests in the Far East. It is curious, in this connection, to remember that Spain's motive in founding her California colonies, four generations ago, was, on the temporal side, the more strongly to establish herself in the Philippines. Strangest of all stories is that of Salt Lake City, the product of religious zeal seeking a supposedly inaccessible desert as a haven from persecution. Finally, when the laborious development of the wilderness has brought rich fruitage, this hermit city finds itself a station on one of the world's most-travelled highways. The coming of the railway, and the consequent practical abandonment of the waterway, wrought a profound change in the fortunes of the Western towns. The railway paid small heed to watercourses, save in mountainous country; it struck out upon short-cuts over the plains and prairies, almost regardless of topography. Hundreds of staid and promising river and lake towns received a staggering blow when, for various reasons,--sometimes their own failure to encourage the enterprise,--the railway passed them by and entered rival and often less pretentious communities, which now were quickened into new vigor. A more favorable situation for a bridge across the stream was often the determining factor which caused several towns upon a river to die and the fortunate one to be transformed into a metropolis. The arbitrary erection throughout the West of new paths of commerce, of new centres of distribution, during the decade and a half before the War of Secession, was of itself a revolutionary element in urban history.