<P> A 2017 study attributes the record - long economic expansion of the United States in the recession - free period of 1841--1856 primarily to "a boom in transportation - goods investment following the discovery of gold in California ." </P> <P> The Gold Rush propelled California from a sleepy, little - known backwater to a center of the global imagination and the destination of hundreds of thousands of people . The new immigrants often showed remarkable inventiveness and civic - mindedness . For example, in the midst of the Gold Rush, towns and cities were chartered, a state constitutional convention was convened, a state constitution written, elections held, and representatives sent to Washington, D.C. to negotiate the admission of California as a state . </P> <P> Large - scale agriculture (California's second "Gold Rush") began during this time . Roads, schools, churches, and civic organizations quickly came into existence . The vast majority of the immigrants were Americans . Pressure grew for better communications and political connections to the rest of the United States, leading to statehood for California on September 9, 1850, in the Compromise of 1850 as the 31st state of the United States . </P> <P> Between 1847 and 1870, the population of San Francisco increased from 500 to 150,000 . The Gold Rush wealth and population increase led to significantly improved transportation between California and the East Coast . The Panama Railway, spanning the Isthmus of Panama, was finished in 1855 . Steamships, including those owned by the Pacific Mail Steamship Company, began regular service from San Francisco to Panama, where passengers, goods and mail would take the train across the Isthmus and board steamships headed to the East Coast . One ill - fated journey, that of the S.S. Central America, ended in disaster as the ship sank in a hurricane off the coast of the Carolinas in 1857, with approximately three tons of California gold aboard . </P>

When was the first time gold was discovered