Completion of the First Transcontinental Railroad

Officials and workers of the Union Pacific and the Central Pacific railways held a ceremony on Promontory Summit, in Utah Territory—approximately thirty-five miles away from Promontory Point, the site where the rails were joined—to drive in the Golden Spike on May 10, 1869. The spike symbolized completion of the first transcontinental railroad, an event that connected the nation from coast to coast and reduced a journey of four months or more to just one week.

The First Transcontinental Railroad (known originally as the "Pacific Railroad" and later as the "Overland Route") was a 1,907-mile (3,069 km) contiguous railroad line constructed between 1863 and 1869 across the western United States to connect the Pacific coast at San Francisco Bay with the existing Eastern U.S. rail network at Council Bluffs, Iowa, on the Missouri River. The rail line was built by three private companies: the original Western Pacific Railroad Company between Oakland and Sacramento, California (132 miles (212 km)), the Central Pacific Railroad Company of California eastward from Sacramento to Promontory Summit, Utah Territory (U.T.) (690 miles), and the Union Pacific Railroad Company westward to Promontory Summit from the road's statutory Eastern terminus at Council Bluffs on the eastern shore of the Missouri River opposite Omaha, Nebraska (1,085 miles).

Opened for through traffic on May 10, 1869, with the driving of the "Last Spike" with a silver hammer at Promontory Summit, the road established a mechanized transcontinental transportation network that revolutionized the settlement and economy of the American West by bringing these western states and territories firmly and profitably into the "Union" and making goods and transportation much quicker, cheaper and much more flexible from coast to coast.

Paddle steamers linked Sacramento to the cities and their harbor facilities in the San Francisco Bay until 1869, when the CPRR completed and opened the WP grade (which the CPRR had acquired in 1867-68 [N 1]) to Alameda and Oakland (MP 6). (Service between San Francisco (MP 0) and Oakland Pier (MP 6) was provided by ferry.) The CPRR eventually purchased 53 miles of UPRR-built grade from Promontory Summit (MP 828) to Ogden, U.T. (MP 881), which became the interchange point between trains of the two roads. The transcontinental line was popularly known as the Overland Route after the principal passenger rail service that operated over the length of the line until 1962.