Surveying the West
In 1853 Congress authorized funds for the Army Corps of Engineers to survey and report on possible routes for a railroad from the Mississippi River to the Pacific Ocean. Army engineers were experienced in surveying the West, and the military had an interest in preparing for westward expansion. Captain George B. McClellan, a West Point graduate and engineer, led a surveying party on the 49th parallel. He later served as General-in-Chief of the Union Armies during the Civil War.