Book excerpt: In 1803 Lewis and Clark set out on their epic expedition across the American wilderness west of the Mississippi, armed with the typical weapon of their day, the single-shot muzzle-loading rifle. By 1865, a variety of breech-loading and repeating arms had been invented there were both easier to use and more accurate. This encyclopaedic study, part one of a two-part book, traces the development and uses of firearms on the frontier during that period, drawing on primary sources such as correspondence and diaries, newspaper accounts, government reports, and patent materials. Then, as now, most of the advances in weaponry were made in response to the military's needs, becoming available somewhat later to civilians, and then to Indians. The authors thoroughly cover the refinements and adaptations of weapons for employ by these three groups and by explorers and trappers, describing in detail each gun, its modifications, operations, and uses. In many ways the history of firearms on the frontier parallels the history of the development of the West.