Here, on January 8, 1863, Governor Leland Stanford turned the first spade of earth to begin construction of the Central Pacific Railroad. After more than six years of labor, crews of the Central Pacific Railroad from the west and the Union Pacific Railroad from the east met at Promontory, Utah where, on May 10, 1869, Stanford drove the gold spike signifying completion of the First Transcontinental Railroad. The Central Pacific Railroad, forerunner of the Southern Pacific Company, was planned by Theodore D. Judah and constructed largely through the efforts of the 'Big Four'-Sacramento businessmen Leland Stanford, Collis P. Huntington, Charles Crocker, and Mark Hopkins.

Citation from California Office of Historic Preservation