The Pacific Railroad Surveys (1853 - 1855) were established in 1853 with the goal of identifying the best possible routes for a transcontinental railroad from the Mississippi to the Pacific. The need for transcontinental railroad made itself evident shortly after the California Gold rush when the westward expansion was at its heights. The federal government, acting under the Sectary of War, Jefferson Davis (of Civil War fame), initiated a series of expeditions of the western territories. These expeditions included surveyors, cartographers, artists, zoologists, botanists and geographers. The resultant work, a 12 volume compendium entitled Reports of Explorations and Surveys, to ascertain the most practicable and economical route for a railroad from the Mississippi River to the Pacific Ocean eventually led to the constructions of several different transcontinental railroads.