The California gold rush (1848–1855) was a gold rush in California, which began on January 24, 1848, when gold was found by James W. Marshall at Sutter's Mill in Coloma, California. The news of gold brought approximately 300,000 people from the rest of the United States and abroad to California, which had recently been conquered from Mexico. The sudden influx of gold into the money supply reinvigorated the American economy; the sudden population increase allowed California to grow rapidly into statehood in the Compromise of 1850. The gold rush had severe effects on Native Californians and accelerated the Native American population's decline from factors including disease, starvation, and according to certain sources, acts of unprovoked aggression.
The effects of the gold rush were substantial. The arrival of large numbers of "forty-niners" (referring to 1849, the peak year for gold rush immigration) led to significant conflict between the newcomers and indigenous people, eventually resulting in whole tribes being displaced in some cases. Outside of California, the first to arrive were from Oregon, Hawaii, and Latin America in late 1848. Of the approximately 300,000 people who came to California during the gold rush, about half arrived by sea and half came overland on the California Trail and the California Road; forty-niners often faced substantial hardships on the trip. While most of the newly arrived were Americans, the gold rush attracted thousands from Latin America, Europe, Australia, and China. Agriculture and ranching expanded throughout the state to meet the needs of the settlers. 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; the future state's interim first governor and legislature were chosen. In September 1850, California achieved statehood.
At the beginning of the gold rush, there was no law regarding property rights in the goldfields and a system of "staking claims" was developed. Prospectors retrieved the gold from streams and riverbeds using simple techniques, such as panning. Although mining caused environmental harm, more sophisticated methods of gold recovery were developed and later adopted around the world. New methods of transportation developed as steamships came into regular service. By 1869, railroads were built from California to the eastern United States. 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 US dollars was recovered, which led to great wealth for a few, though many who participated in the California gold rush earned little more than they had started with.
Gold was discovered in California as early as March 9, 1842, at Rancho San Francisco, in the mountains north of present-day Los Angeles. Californian native Francisco Lopez was searching for stray horses and stopped on the bank of a small creek (in today's Placerita Canyon), about 3 miles (4.8 km) east of present-day Newhall, and about 35 miles (56 km) northwest of Los Angeles. While the horses grazed, Lopez dug up some wild onions and found a small gold nugget in the roots among the bulbs. He looked further and found more gold. Lopez took the gold to authorities who confirmed its worth. Lopez and others began to search for other streambeds with gold deposits in the area. They found several in the northeastern section of the forest, within present-day Ventura County. In November, some of the gold was sent to the U.S. Mint, but otherwise attracted little notice. In 1843, Lopez found gold in San Feliciano Canyon near his first discovery. Mexican miners from Sonora worked the placer deposits until 1846. Minor finds of gold in California were also made by Mission Indians prior to 1848. The friars instructed them to keep its location secret to avoid a gold rush.
In January 1847, nine months into the Mexican–American War, the Treaty of Cahuenga was signed, leading to the resolution of the military conflict in Alta California (Upper California). On January 24, 1848, James W. Marshall found shiny metal in the tailrace of a lumber mill he was building for Sacramento pioneer John Sutter—known as Sutter's Mill, near Coloma on the American River. Marshall brought what he found to Sutter, and the two privately tested the metal. After the tests showed that it was gold, Sutter expressed dismay, wanting to keep the news quiet because he feared what would happen to his plans for an agricultural empire if there were a gold rush in the region. The Mexican–American War ended on May 30 with the ratification of the Treaty of Guadalupe Hidalgo, which formally transferred California to the United States.
Having sworn all concerned at the mill to secrecy, in February 1848, Sutter sent Charles Bennett to Monterey to meet with Colonel Mason, the chief U.S. official in California, to secure the mineral rights of the land where the mill stood. Bennett was not to tell anyone of the discovery of gold, but when he stopped at Benicia, he heard talk about the discovery of coal near Mount Diablo, and he blurted out the discovery of gold. He continued to San Francisco, where again, he could not keep the secret. At Monterey, Mason declined to make any judgement of title to lands and mineral rights, and Bennett for the third time revealed the gold discovery.
By March 1848, rumors of the discovery were confirmed by San Francisco newspaper publisher and merchant Samuel Brannan. Brannan hurriedly set up a store to sell gold prospecting supplies, and he walked through the streets of San Francisco, holding aloft a vial of gold, shouting "Gold! Gold! Gold from the American River!"
On August 19, 1848, the New York Herald was the first major newspaper on the East Coast to report the discovery of gold. On December 5, 1848, US president James K. Polk confirmed the discovery of gold in an address to Congress. As a result, individuals seeking to benefit from the gold rush—later called the "forty-niners"—began moving to the Gold Country of California or "Mother Lode" from other countries and from other parts of the United States. As Sutter had feared, his business plans were ruined after his workers left in search of gold, and squatters took over his land and stole his crops and cattle.
San Francisco had been a tiny settlement before the rush began. When residents learned about the discovery, it at first became a ghost town of abandoned ships and businesses, but then boomed as merchants and new people arrived. The population of San Francisco increased quickly from about 1,000 in 1848 to 25,000 full-time residents by 1850. Miners lived in tents, wood shanties, or deck cabins removed from abandoned ships. There were no churches or religious services in the rapidly growing city, which prompted missionaries like William Taylor to meet the need, where he held services in the street, using a barrel head as his pulpit. Crowds would gather to listen to his sermons, and before long he received enough generous donations from successful gold miners and built San Francisco's first church.
In what has been referred to as the "first world-class gold rush," there was no easy way to travel to California; forty-niners faced hardship and often death on the way. At first, most Argonauts, as they were also known, traveled by sea. From the East Coast, a sailing voyage around the tip of South America would take four to five months, and cover approximately 18,000 nautical miles (21,000 mi; 33,000 km). An alternative was to sail to the Atlantic side of the Isthmus of Panama, take canoes and mules for a week through the jungle, and then on the Pacific side, wait for a ship sailing for San Francisco. There was also a route across Mexico starting at Veracruz. The companies providing such transportation generated vast amounts of wealth among their owners, including the U.S. Mail Steamship Company, the federally subsidized Pacific Mail Steamship Company, and the Accessory Transit Company. Many gold-seekers took the overland route across the continental United States, particularly along the California Trail. Each of these routes had its own deadly hazards, from shipwreck to typhoid fever and cholera. In the early years of the rush, much of the population growth in the San Francisco area was due to steamship travel from New York City through overland portages in Nicaragua and Panama and then back up by steamship to San Francisco.