On 24 January 1848, a carpenter named James Marshall was inspecting a sawmill he was building for his boss, John Sutter, on the American River in California. The water flowing through the mill's tailrace had washed away the gravel. Marshall bent down and picked up a shiny yellow flake about the size of a pea. He bit it. It was soft. He pounded it with a rock. It bent instead of shattering. His heart started racing. It was gold.
Sutter and Marshall tried to keep it a secret, but secrets like that never last. By spring, a Mormon storekeeper named Sam Brannan was running through the muddy streets of San Francisco waving a small bottle of gold dust and yelling that there was gold in the American River. The town emptied out almost overnight. Sailors abandoned ships in the bay. Soldiers walked off their posts. By 1849 the news had spread across the world, and around 300,000 people - the famous 'forty-niners' - poured into California from China, Mexico, Chile, France, Australia, Ireland, and across the United States.
Most found very little gold and made their money instead by selling shovels, pickaxes, jeans, and pancakes to the miners. A young salesman named Levi Strauss made his fortune sewing tough denim trousers. San Francisco swelled from a sleepy village of 800 people to a roaring city of 25,000 in just two years. California, which had only just become U.S. territory, became a full state in 1850. The whole rhythm of the American West - its railroads, its cities, its rush-and-risk culture - was set in motion by one yellow pebble in a streambed.
