Gold was discovered near Coloma in the Sierra Nevada in June 1848, days before Mexico ceded California to the USA. As the news spread, the effect was electrifying. The first wave of the Gold Rush was seaborne, from Hawaii, China and Latin America, and overland from adjoining Oregon Territory. Within a year, huge numbers had also arrived from the east. By 1850, California’s non-native population had exploded from less than 10,000 to 100,000: the Compromise of that year fast-tracked its statehood. Wherever gold was found gold-mining towns – replete with shops, saloons and brothels – quickly followed. But within the decade, surface gold deposits in central California were becoming depleted. The epicentre then moved east to Nevada, where silver was discovered near Virginia City. The rushes were ephemeral but their effects permanent: they were catalysts for revolutions in communications (the transcontinental telegraph and railroad were completed 1861 and 1869 respectively) and transformed San Francisco into a major port.