Proposed routes and selected route for the U.S. Pacific Railroad
Congress considered the merits of the four U.S. Pacific Railroad Expedition surveys–along the 32nd, 35th, 37th - 39th, and 47th- 49th parallels–and finally selected a different, middle route.
A Railroad to the Pacific - 2
Settlement of the western territories in the 1850s increased the need for efficient rail transport to the Pacific Coast, but members of Congress could not agree on what route it should follow. Northern members wanted a northern route; southern members sought one advantageous to their region's interests. To inform this debate, in 1853 Congress authorized the Army Corps of Engineers to survey four potential rail routes. Intense sectionalism blocked further legislation until southern states seceded. In 1862, a northern-controlled Congress passed the Pacific Railroad Act.