The Great Platte River Road through Nebraska and Wyoming was the grand corridor of America's westward expansion. A number of famous trails converged in the broad valley of the Platte, forming a kind of primitive superhighway for the great covered wagon migration from 1841 to 1866. From jumping-off places along the Missouri River-notably the Omaha-Council Bluffs, St. Joseph, and Kansas City areas-the emigrant throngs came together at Fort Kearny, Nebraska...