In the 1860s a Railroad was planned that would tie the West Coast to the rest of the United States, boost trade, greatly shorten travel time and allow the army to control American Indians unhappy with western expansion. Theodore Judah, a young engineer, surveyed a route over the Sierra Nevada Mountains of California and persuaded some wealthy Sacramento merchants to form the Central Pacific Railroad in 1861. These Sacramento merchants became known as the Big Four of the Central Pacific Railroad: Leland Stanford, Collis Huntington, Charles Crocker and Mark Hopkins. Stanford became president, Huntington vice-president, Crocker field manager and Hopkins treasurer of the Central Pacific Railroad.

In 1862 Congress passed the Railroad Act, which was signed by President Lincoln. This Act established the Union Pacific Railroad. Thomas Durant became the vice-president and active head of this railroad. Oaks Ames became the principal financial backer during the construction years.

The Central Pacific started building railroad from Sacramento, California in January, 1863, and the Union Pacific started building from Omaha, Nebraska in December, 1863. Though construction officially started in 1863, it wasn't until 1865 that the companies started building track in earnest.

After building a few miles of track, the Central Pacific ran into the Sierra Nevada Mountains which greatly slowed construction. Most of the supplies and equipment for the Central Pacific had to be shipped around the Cape Horn at the tip of South America. This meant that if they ran out of something, like iron rails, they had to order it from the East and wait from three to seven months or longer for it to be shipped to them. Because workmen kept disappearing to the gold and silver mines, the Central Pacific hired Chinese laborers to build their part of the Railroad. Beginning in 1865 it took the Central Pacific three long years to build track through the Sierra Nevada Mountains. By 1868 they were through the Mountains and building railroad across the Great Basin country of Nevada. This was Paiute and Shoshone Indian country and the Central Pacific offered the American Indians jobs working on the railroad. Also to reduce conflict with the American Indians James Strobridge, the construction superintendent of the Central Pacific, gave them free rides on the train. The Central Pacific built track through California, Nevada and into Utah Territory.

The Civil War slowed construction of the Union Pacific, but after the war ended in 1865, the Union Pacific began to build railroad at a fast pace from Omaha across the flat ground of Nebraska. Many of the Union Pacific Railroad workers were Irishmen who had served as soldiers in the Civil War. Jack Casement supervised the Union Pacific construction crews and Grenville Dodge was the chief engineer. The Union Pacific workmen ran into large Buffalo herds which they used as a source of food. They also had many confrontations with angry Sioux, Cheyenne and Arapaho Indian warriors. These warriors often tore up the track of the Union Pacific. Their track was was also washed out by spring floods on many occasions. This slowed the construction of the Union Pacific because they had to go back and repair the track. The Union Pacific built track through Nebraska, Wyoming and into Utah Territory.

In 1869 the two companies decided that they would join their track at a place called Promontory Summit, Utah. This place is located on the north side of the Great Salt Lake. Just before completion of the Railroad the Central Pacific set a record 10 miles of track laid in one day, a record that has never been surpassed by man or machine.

At the celebration held on May 10th, 1869 there were four precious metal spikes used to commemorate the completion of the first transcontinental railroad. It was a momentous occasion and a major turning point in American history.