The California Gold Rush began on January 24, 1848, when gold was found by James W. Marshall at Sutter's Mill in Coloma, California. As the rumor spread, new settlers started flocking to the state in late 1848. The news of gold brought some 300,000 people from the rest of the United States and abroad, some by sea and some overland on the California Trail and the Gila River trail. The gold-seekers were called "forty-niners", as a reference to 1849.
At first, the prospectors retrieved the gold from streams and riverbeds using simple techniques, such as panning. More sophisticated methods of gold recovery were developed and later adopted around the world. At its peak, technological advances reached a point where significant financing was required, increasing the proportion of gold companies to individual miners. Gold worth tens of billions of today's dollars was recovered, which led to great wealth for a few. However, many returned home with little more than they had started with.
The effects of the Gold Rush were far reaching. San Francisco grew from a small settlement of about 200 residents in 1846 to a boomtown of about 36,000 by 1852. Roads, churches, schools and other towns were built throughout California. In 1849 a state constitution was written. The new constitution was adopted by referendum vote, and the future state's interim first governor and legislature were chosen. In September 1850, California became a state.
US gold production greatly increased during the 1980s, due to high gold prices and the use of heap leaching to recover gold from disseminated low-grade deposits in Nevada and other states.
In 2015 the United States produced 200 tonnes of gold, 6.7% of world production. Most gold produced today in the US comes from large open-pit heap leach mines in the state of Nevada.
