Before the Civil War, people in America (and their government leaders) knew a transcontinental railroad was needed to better unite the country. As early as 1832, The Emigrant (an Ann Arbor newspaper) called for a national railroad line. But slavery issues, among others, kept North and South from agreeing on the best route. Once the Southern States had seceded from the Union, however, Congress was free to proceed as its remaining members wished.
The Railroad Act of 1862 (as subsequently amended in 1864 and 1866) chartered the Union Pacific Railroad Company. It competitively teamed with the newly created Central Pacific Railroad Company of California to lay down track from San Francisco, California (on the west end) to Omaha, Nebraska (on the east end). Each side raced to see which company could build the line more quickly.
It would have been hard enough to build the railroad if the terrain were flat, like in the plains. But rugged territories (like the Sierra Nevada mountains) were also part of the equation, as were trestle bridges (which required exquisite planning and engineering) and Indians (who, like these Cheyenne, were most upset that the railroad was invading their territories):
Building the railroad was not the only difficulty workers faced. By today’s standards, their living (and working) conditions were atrocious:
By the spring of 1869 (despite tremendous obstacles, after less than a decade of building and seven years ahead of schedule), workers on both parts of the track were about to meet.