On May 10, 1869, in what is now northern Utah, the Union Pacific Railway and the central Pacific Railway joined to form the first Trans American Railway. In order to commemorate this achievement, a special "gold nail" was nailed at the joint of the two railways. Since then, the "golden nail" has become a symbol of important geographical location and has also been borrowed into stratigraphy. The "gold nail" of stratigraphy is the common name of the professional term "global stratotype section and point".