"A DRY GULCH" AT COLOMA, SUTTER'S MILLS; May 2, 1850 235 MAP OF AUDUBON'S ROUTE _At end of volume_ INTRODUCTION Ordinarily events are the result of antecedent causes, but now and then an apparently fortuitous incident upsets all calculations and changes the course of history in a day. Of such a character was the discovery of gold in California. It would be difficult to overstate its importance. It led directly to a similar discovery in Australia and the combined output of the two fields replenished the world's stock of precious metals, shaped monetary systems, stimulated prices and powerfully affected the economic and industrial development of the last half century. Politically for the United States the discovery was the turning point in the struggle between the sections. Texas had been annexed and the South West wrung from Mexico largely for the purpose of equalizing slave and free territory by providing the South with an outlet for Western emigration comparable in extent with that possessed by the North. The instantaneous settlement of California under circumstances unfavorable to slavery produced a free state and gave the North a majority in the Senate. The attempt to recover the lost ground brought on the Kansas struggle and precipitated the war that destroyed the only real cause of antagonism between the sections. Socially the results of the discovery were not less important. Immediately a new state was added to the Union. Ultimately the necessity of joining the new state to the older ones opened the West to settlement, built the trans-continental railways, reclaimed the desert and peopled the continent. Fifty years ago Congress was petitioned to import "thirty camels and twenty dromedaries" and their use as a means of crossing the Western deserts was seriously discussed in books and newspapers.[1] Today there is no part of this vast territory that is not within easy reach of the railroad. Of the remarkable things accomplished in the United States perhaps the most remarkable is the rapid movement of population from seaboard to seaboard, and yet this movement has been strangely neglected by historians. They follow minutely the course of Coronado and Radisson but know little of J. S. Smith and scarcely take the trouble to trace the routes of even so famous an explorer as John C. Fremont. They devote much space to the difficulties of settling Jamestown and Plymouth and very little to the hardships of the overland journey. They carefully trace the campaigns of the War of 1812 but barely mention the wars that have won the continent from the Indians. As throwing a side-light upon one phase of this neglected movement Audubon's "Journal" is presented to the public. But quite apart from this, the book is interesting as a human document. Not only does it reflect the energy and strength of character of the author but the glimpse it gives of the constancy of the