The First Transcontinental Railroad in the United States was built across North America in the 1860s, linking the railway network of the Eastern United States with California on the Pacific coast. Ceremonially completed on May 10, 1869, at the famous "golden spike" event at Promontory Summit, Utah, it created a nation-wide mechanized transportation network that revolutionized the population and economy of the American West. This network caused the wagon trains of previous decades to become obsolete, exchanging it for a modern transportation system.
Authorized by the Pacific Railway Act of 1862 and heavily backed by the federal government, it was the culmination of a decades-long movement to build such a line and was one of the crowning achievements of the presidency of Abraham Lincoln, completed four years after his death. The building of the railway required enormous feats of engineering and labor in the crossing of plains and high mountains by the Union Pacific Railroad and Central Pacific Railroad, the two privately chartered federally backed enterprises that built the line westward and eastward respectively.
The building of the railroad was motivated in part to bind the Union together during the strife of the American Civil War. It substantially accelerated the populating of the West by white homesteaders, while contributing to the decline of the Native Americans in these regions. In 1879, the Supreme Court of the United States formally established, in its decision regarding Union Pacific Railroad vs. United States (99 U.S. 402), the official "date of completion" of the Transcontinental Railroad as November 6, 1869.
The Central Pacific and the Southern Pacific Railroad combined operations in 1870 and formally merged in 1885. Union Pacific originally bought the Southern Pacific in 1901 but in 1913 was forced to divest it; the company once again acquired the Southern Pacific in 1996. Much of the original right-of-way is still in use today and owned by the Union Pacific.
The railroad was considered the greatest American technological feat of the 19th century. It served as a vital link for trade, commerce and travel that joined the eastern and western halves of late 19th century United States. The transcontinental railroad quickly ended the romantic yet far slower and more hazardous stagecoach lines that had preceded it. The subsequent march of "Manifest Destiny" and proliferation of the so-called "Iron Horse" across Native American land greatly accelerated the demise of Great Plains Indian culture.
