At which Utah site did the first U.S. transcontinental railroad officially meet in 1869?

The first U.S. transcontinental railroad officially met at Promontory Summit, Utah, in 1869.

On May 10, 1869, the Union Pacific and Central Pacific railroads joined their tracks at Promontory Summit in Utah Territory. Leland Stanford, president of the Central Pacific, ceremonially drove the final “Last Spike,” often called the Golden Spike. The event connected the existing eastern rail network with the Pacific coast and opened the route for through traffic between Sacramento and Omaha.

The Union Pacific built westward from the Missouri River region, while the Central Pacific built eastward from Sacramento. Chinese workers formed a large part of the Central Pacific workforce, and Irish immigrants were prominent among Union Pacific laborers. The construction crossed plains, deserts, and the Sierra Nevada.

Promontory Summit is sometimes confused with Promontory Point, a different location farther south. The original route through Promontory was later bypassed by the Lucin Cutoff, and the old alignment was eventually abandoned. The railroad's later extension to the San Francisco Bay completed the route to its western terminal.