For every successful mining district celebrated in history, there were failed dozens whose stories have been largely forgotten. The Mechanics of Optimism documents, in rare detail, the boom-bust cycle of Hot Spring District, a mid-1860s Montana gold camp that did not pay, despite early predictions of a sure thing. Historian Jeffrey J. Safford examines how gold mining ventures were developed and financed during and after the Civil War, and how men, primarily Easterners with scant knowledge of mining, were willing to invest large sums in gold mines that promised quick and lucrative returns. Safford explains how these mining companies were organized and underwritten, and why a little-known district in southwestern Montana was chosen as a center of operations. Relying on extensive primary sources, Safford addresses the mind-set of the businessmen, the expectations and realities of new mining technology, the financial strategies, and the universality of the Hot Spring experience.