Menu Welcome to UCRFA In 1865 Chinese immigrants were enlisted by the Central Pacific Railroad in the building of the western section of the First Transcontinental Railroad. Between 1865 and May 10 1869 when the Golden Spike was driven with a silver hammer at Promontory Summit it was estimated up to 15000 Chinese the majority of the labor force had been working tirelessly over and through the granite walls of the Sierra Nevada and the blistering desert of Nevada. The First Transcontinental Railroad united California and the other western states to the eastern part of the country. With newlyopened markets in the east there was rapid growth in Californias agricultural production which was later followed by growth in other economical forms as well.