Transcontinental rail service in the United States began in the 1860s. The first transcontinental railroad, connecting the eastern and western U.S., was completed on May 10, 1869 , at Promontory Summit, Utah, when the Union Pacific and Central Pacific Railroads met with a ceremonial golden spike.

Key Timeline

Construction started in 1863 under the Pacific Railway Act of 1862, signed by President Abraham Lincoln. By 1869, the 1,911-mile line from Council Bluffs, Iowa, to Oakland, California, opened for regular service on May 15, 1869 , slashing cross-country travel from months to about a week.

Historical Impact

  • Economic Boom : Freight and passengers surged, revolutionizing trade and settlement in the West.
  • Worker Stories : Thousands of Chinese and Irish laborers endured harsh conditions, blasting through the Sierra Nevada and Plains.
  • Cultural Shift : It unified the nation post-Civil War, boosting migration but disrupting Native lands.

This milestone defined the 1860s decade (1860–1869) as the start, with full public use by decade's end. TL;DR : 1860s, completed 1869. Information gathered from public forums or data available on the internet and portrayed here.