“Done.”

Telegraph message announcing the completion of the transcontinental railroad, May 10, 1869

The question of "internal improvements" was constantly before Congress in the 19th century: Should Congress assist in improving the country’s transportation system? One such improvement was the dream of constructing a railroad that would cross the entire country. In the 1850s Congress commissioned several topographical surveys across the West to determine the best route for a railroad, but private corporations were reluctant to undertake the task without Federal assistance. In 1862 Congress passed the Pacific Railroad Acts which designated the 32nd parallel as the initial transcontinental route and gave huge grants of lands for rights-of-way.

The legislation authorized two railroad companies, the Union Pacific and the Central Pacific, to construct the lines. Beginning in 1863, the Union Pacific, employing more than 8,000 Irish, German, and Italian immigrants, built west from Omaha, Nebraska; the Central Pacific, whose workforce included over 10,000 Chinese laborers, built eastward from Sacramento, California. Each company faced unprecedented construction problems—mountains, severe weather, and the hostility of Native Americans. On May 10, 1869, in a ceremony at Promontory, Utah, the last rails were laid and the last spike driven. Congress eventually authorized 4 transcontinental railroads and granted 174 million acres of public lands for rights-of-way.