The Last Spike, also known as the Gold Spike, was the final link in the forming of the first transcontinental railroad in the United States. It was tapped into a prepared hole by Leland Stanford on May 10, 1869, at a ceremony joining the Central Pacific and Union Pacific rails. Governor Stanford drove the Last Spike into a polished California laurel tie before an audience of some 3,000 government and railroad officials and track workers in the desert at Promontory, Utah.

The spike was the inspiration of David Hewes, prominent building contractor and financier of San Francisco and the brother-in-law of Mrs. Stanford. Immediately after the ceremony, the spike and laurel tie were withdrawn and an iron spike and regular tie substituted. Mr. Stanford presented the Last Spike to Mr. Hewes, who in turn presented it to the Stanford Museum in 1892.

Resembling an ordinary railroad spike in size and design, the Last Spike was manufactured by the William T. Garrett Foundry of San Francisco in 1869. The spike is 17.6 carat gold, alloyed with copper, and weighs 14.03 troy ounces. Clearly visible on its head are the dents made by Governor Stanford when he tapped it with a silver hammer. It is engraved on the top and on all four sides. On the head are the words "The Last Spike;" on side one: "The Pacific Railroad ground broken Jany. 8th 1863, and completed may 8th 1869" (the ceremony was to take place on May 8th but was delayed by adverse weather and labor problems that held up the Union Pacific delegation); on side two: "Directors of the C. P. R. R. of Cal. Hon. Leland Stanford. C. P. Huntington. E. B. Crocker. Mark Hopkins. A. P. Stanford. E. H. Miller Jr.;" on side three: "Officers. Hon. Leland Stanford. Presdt. C. P. Huntington Vice Presdt. E. B. Crocker. Atty. Mark Hopkins. Tresr. Chas Crocker Gen. Supdt. E. H. Miller Jr. Secty. S. S. Montague. Chief Engr.;" and on side four: "May God continue the unity of our Country, as the Railroad unites the two great Oceans of the world. Presented by David Hewes San Francisco."

Two other spikes were used at the last spike ceremony, another gold spike donated by Frank Marriott, owner of the San Francisco Newsletter, and a composite spike of gold, silver and iron - a gift from the Arizona Territory.