The first transcontinental railroad across the United States opened in 1869.
The Central Pacific Railroad built eastward from Sacramento, California, while the Union Pacific Railroad built westward from Omaha, Nebraska. Their tracks were connected at Promontory Summit in Utah Territory on May 10, 1869.
The meeting was marked by the driving of a ceremonial golden spike. The railroad created a continuous rail route across the country, cutting travel between the Missouri River and the Pacific Coast from several months to roughly a week under favorable conditions.
The project depended heavily on immigrant labor, including thousands of Chinese workers on the Central Pacific and Irish and other laborers on the Union Pacific. Its construction also brought severe disruption to Indigenous nations and accelerated settlement, commercial expansion, and military movement across the West.