Construction proceeded in earnest in 1865 when James Harvey Strobridge, the head of the construction work force, hired the first Cantonese emigrant workers at Crocker's suggestion. The construction crew grew to include 12,000 Chinese laborers by 1868, when they constituted eighty percent of the entire work force. The "Golden spike", connecting the western railroad to the Union Pacific Railroad at Promontory, Utah, was hammered on May 10, 1869. Coast-to-coast train travel in eight days became possible, replacing months-long sea voyages and lengthy, hazardous travel by wagon trains.