Promontory Summit is a historic site in Utah, known for being the location where the first transcontinental railroad was completed on May 10, 1869. This event marked a significant milestone in American history, connecting the eastern and western parts of the United States. The joining of the Central Pacific Railroad and the Union Pacific Railroad at this summit facilitated trade, travel, and communication across the country. The site features the iconic Golden Spike, which symbolizes the completion of the railroad. Today, Promontory Summit is part of the Golden Spike National Historical Park, where visitors can learn about the impact of the railroad on the nation and see reenactments of the historic event.