It was an awesome sight, that regiment of Mounted Riflemen slowly marching up the Oregon Trail, already crowded with gold seekers and their animals in 1849. In May of that year five companies of men and 171 supply wagons started from Fort Leavenworth on a five-month, two-thousand-mile march that would take them to Fort Vancouver. After distinguished service in the Mexican War, the rifle regiment had mustered out and then reorganized for the purpose of establishing and garrisoning forts along the Oregon Trail. The March of the Mounted Riflemen, first published in 1940, is important as the only...