The idea of a gold spike came from David Hewes, a San Francisco financier and contractor with a flair for the dramatic. He commissioned the spike especially for the May ceremony, having two sides engraved with the names of railroad officers and directors. The event itself drew somewhere between 500 and 3,000 people to Promontory Summit, a remote point in Utah Territory where the Central Pacific from Sacramento met the Union Pacific from Omaha. Government officials, railroad executives, and track workers gathered to witness history. After the ceremony, the spike was taken to California by Hewes and eventually donated to Stanford University in 1892, where it remains today. A companion ceremonial spike, the Arizona Spike made of gold and silver, was sold at auction in January 2023 for approximately $2.2 million.

A common myth holds that no Chinese workers appear in the famous photographs of the ceremony. This is false. Stanford University's Chinese Railroad Workers in North America Project identified two Chinese laborers in Andrew J. Russell's iconic "handshake" photograph. More appear in Russell's stereo view #539, titled "Chinese at Laying Last Rail UPRR." The truth is that more than 12,000 Chinese workers built the Central Pacific line, comprising 80% of its workforce. Eight Chinese workers laid the final rail from the east. Three of them, Ging Cui, Wong Fook, and Lee Shao, lived to participate in the 50th anniversary parade at Ogden, Utah, in 1919. At the conclusion of the 1869 ceremony, Central Pacific construction chief J. H. Strobridge honored the Chinese workers with dinner in his private railroad car.

The Promontory ceremony marked a milestone, but not the finish line. Neither Sacramento nor Omaha was a seaport, and neither had rail connections when designated as termini. Western Pacific completed the line from Sacramento to San Francisco Bay on September 6, 1869. The U.S. Supreme Court later determined the official completion date of the Pacific Railroad to be November 6, 1869. Passengers still had to cross the Missouri River by boat between Council Bluffs and Omaha until the Union Pacific Missouri River Bridge opened in March 1872. A true coast-to-coast link came in August 1870, when the Kansas Pacific Railway completed its Denver extension to Strasburg, Colorado.

By 1904, the Promontory route was obsolete. The new Lucin Cutoff crossed the Great Salt Lake directly from Ogden to Lucin, cutting 43 miles from the journey. Main line trains no longer passed over Promontory Summit. In 1942, the original rails were pulled up for World War II scrap, marked by a ceremonial "undriving" of the last iron spike. Local residents erected a marker in 1943. A commemorative stamp was issued for the 75th anniversary in 1944. The first re-enactment was staged in 1948. Congress established Golden Spike National Historic Site in 1957, and O'Connor Engineering Laboratories built working replicas of the original locomotives. For the 1969 centennial, the High Iron Company ran a steam excursion from New York City, with John Wayne aboard for the final leg into Salt Lake City.

The golden spike has driven its way into American culture. John Ford depicted the ceremony in The Iron Horse (1924), now preserved in the National Film Registry. Wild Wild West (1999) staged a fictional assassination attempt at the ceremony. Hell on Wheels ran multiple seasons on the railroad's construction. Utah chose the golden spike for its state quarter in 2006. In 2019, the Postal Service issued three commemorative stamps for the 150th anniversary. That same year, Secretary of Transportation Elaine Chao spoke at the ceremony, bringing overdue focus to the Chinese contribution. A 43-foot statue of the spike is planned for a Utah state park in Brigham City. The symbol endures because it represents something larger than a railroad: the closing of the American frontier, the linking of a continent, the audacity of a young nation convinced it could bend geography to its will.