The Transcontinental Railroad was a railroad built across the United States of America. The building of it started when Abraham Lincoln signed the Pacific Railroad Act of 1862 into law. Much of it was built by the Central Pacific Railroad, building east from Sacramento, California, and the Union Pacific Railroad building West from Omaha, Nebraska. The two railroads met at Promontory Summit, Utah on May 10 in the year 1869. Much of it was built by people who came to the U.S. from China and Ireland. It cut the time to go across the United States from months to weeks and later days. At the time of its completion, it was one of the longest railroads in the world.
- "Profile Showing the Grades upon the Different Routes Surveyed for the Union Pacific Rail Road Between the Missouri River and the Valley of the Platte River". World Digital Library. 1865. Retrieved 2013-07-16.
- "Ceremony at "Wedding of the Rails," May 10, 1869 at Promontory Point, Utah". World Digital Library. 1869-05-10. Retrieved 2013-07-21.