S1, E3: In 1848, a sawmill worker named James Marshall reached down into the stream bed of the American River in California -- and came up with the future of the West in the palm of his hand. He had discovered gold. During the next year alone, more than 50,000 fortune-seekers swarmed into the Sierra Nevada in a headlong scramble for riches. Like many "49ers," William Swain left his home and family to endure hardships and disappointments for a "pocketful of rocks." Wild mining camps with names like Whiskey Diggings, Grizzly Flat and Murders' Bar sprang up -- and then disappeared with each new strike. A once-sleepy village on a magnificent bay changed overnight into the thriving international city of San Francisco; a merchant declared himself "Emperor of North America"; and a shrewd Mormon shopkeeper became the gold rush's first millionaire. But with the overwhelming influx of Americans, thousands of Indians were killed in the pursuit of land and slave labor, foreign miners were coerced from mining and Mexican-Americans lost their land. The Gold Rush changed the West forever.