The Central Pacific Railroad Company of California (CPRR) constructed 690 miles (1,110 km) east from Sacramento to Promontory Summit, Utah Territory.

The Union Pacific Railroad (UPRR) built 1,085 miles (1,746 km) from the road's eastern terminus at the Missouri River settlements of Council Bluffs and Omaha, Nebraska, westward to Promontory Summit.

One Congressman referring to the West, bluntly stated that “All that land wasn’t worth ten cents until the railroads came.”[28][29] Freight rates by rail were a small fraction of what they had been with wagon transport.

While serving as vice president of Union Pacific he would be a key figure in the Crédit Mobilier scandal which ultimately led to his removal from the company.

The legislation called for building and operating a new railroad from the Missouri River at Council Bluffs, Iowa, west to Sacramento, California, and on to San Francisco Bay.

Huntington persuaded Judah to accept financing from himself and four others: Mark Hopkins, his business partner; James Bailey, a jeweler; Leland Stanford, a grocer; and Charles Crocker, a dry-goods merchant.

The Central Pacific hired some Canadian and European civil engineers and surveyors with extensive experience building railroads, but it had a difficult time finding semi-skilled labor.

[citation needed] Wooden timbers for railroad ties, trestles, bridges, firewood, and telegraph poles were harvested in California and transported to the project site.

[citation needed] The rails used initially in building the railway were nearly all made of an iron flat-bottomed modified I-beam profile weighing 56 or 66 pounds per yard (27.8 or 32.7 kg/m).

The original westward travelers in their ox and mule pulled wagons tried to stick to river valleys to avoid as much road building as possible—gradients and sharp corners were usually of little or no concern to them.

[103] The new route surveyed across Wyoming was over 150 miles (240 km) shorter, had a flatter profile, allowing for cheaper and easier railroad construction, and also went closer by Denver and the known coalfields in the Wasatch and Laramie Ranges.

Its location made it a good base for helper locomotives to couple to trains with snowplows to help clear the tracks of snow or help haul heavy freight over Evans pass.

On December 4, 1868, the Union Pacific reached Evanston, having laid almost 360 miles (580 km) of track over the Green River and the Laramie Plains that year.

A steam engine off an old locomotive was brought up with much effort over the wagon road and used as a winch driver to help remove loosened rock from the vertical shaft and two working faces.

One of the most troublesome problems found on this route along the Humboldt was at Palisade Canyon (near Carlin, Nevada), where for 12 miles (19 km) the line had to be built between the river and basalt cliffs.

[124] The CPRR route passed through Newcastle and Truckee in California, Reno, Wadsworth, Winnemucca, Battle Mountain, Elko and Wells in Nevada (with many more fuel and water stops), before connecting with the Union Pacific line at Promontory Summit in the Utah Territory.

Modern-day Interstate 80 roughly follows the path of the railroad from Sacramento across modern day California, Nevada, Wyoming and Nebraska, with a few exceptions.

The Union Pacific train carrying him to the final spike ceremony was held up by a strike by unpaid workers in Piedmont, Wyoming, until he paid them for their work.

Initially, Central Pacific had a hard time hiring and keeping unskilled workers on its line, as many would leave for the prospect of far more lucrative gold or silver mining options elsewhere.

Despite the concerns expressed by Charles Crocker, one of the "big four" and a general contractor, that the Chinese were too small in stature[129] and lacking previous experience with railroad work, they decided to try them anyway.

[131] Almost all of the roadbed work had to be done manually, using shovels, picks, axes, two-wheeled dump carts, wheelbarrows, ropes, scrapers, etc., with initially only black powder available for blasting.

On January 8, 1863, Governor Leland Stanford ceremonially broke ground in Sacramento, California, to begin construction of the Central Pacific Railroad.

After great initial progress along the Sacramento Valley, construction was slowed, first by the foothills of the Sierra Nevada, then by cutting a railroad bed up the mountains themselves.

The major investor in the Union Pacific was Thomas Clark Durant,[144] who had made his stake money by smuggling Confederate cotton with the aid of Grenville M. Dodge.

He paid an associate to submit the construction bid to another company he controlled, Crédit Mobilier, manipulating the finances and government subsidies and making himself another fortune.

Union Pacific responded by increasing security and hiring marksmen to kill American Bison, which were both a physical threat to trains and the primary food source for many of the Plains Indians.

[147] Both railroads soon instituted extensive upgrade projects to build better bridges, viaducts and dugways as well as install heavier duty rails, stronger ties, better road beds etc.

[148] Several years after the end of the Civil War, the competing railroads coming from Missouri finally realized their initial strategic advantage and a building boom ensued.

Kansas City's head start in connecting to a true transcontinental railroad contributed to it rather than Omaha becoming the dominant rail center west of Chicago.

The 1939 movie is said to have inspired the Union Pacific Western television series starring Jeff Morrow, Judson Pratt and Susan Cummings which aired in syndication from 1958 until 1959.