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.