In 1862, during the Civil War, the United States government decided to give money to build a railroad to connect the East with the West. The companies would receive $16,000, $32,000, or $48,000 for each mile of track that was built. the dollar amount varied depending on how difficult it was to lay the track.
The Union Pacific started at Omaha, Nebraska and laid track towards the West. The Central Pacific began at Sacramento, California and built eastward. The two lines were to join somewhere in Utah.
The Union Pacific led by Grenville Dodge faced a huge obstacle. The Plains had no lumber for railroad ties. Timber had to be brought from Minnesota and Michigan. They also had to bring in stone for the roadbed from Wisconsin. Steel rails had to come from Pennsylvania. The crews had to fight the Native American and buffalo herds all the way.
The Central Pacific also faced problems. Their track had to be laid through the Rocky Mountains. The mostly Chinese workers had to work in waist deep snow to get the job done.
On May 10, 1869 the two tracks met at Promontory Point, Utah. A golden spike was driven into the rails to join the two together.
"The Last Spike" by Thomas Hill (1881) depicting the ceremony of the driving of the "Last Spike" at Promontory Summit, UT, on May 10, 1869, joining the rails of the Central Pacific Railroad and the Union Pacific Railroad.
Soon after the tracks were joined more railroads were built. James J. Hill began the Great Northern Railroad in 1879. His railroad ran from Minnesota to Washington State. Hill raised money to build the tracks by selling land along the railroad as it was being built.
Other railroads were also built:
the Southern Pacific
the Northern Pacific