On January 24, 1848, gold was discovered at Sutter’s Mill on the American River in Northern California. After James W. Marshall, who’d been overseeing the sawmill’s construction, found the gold nuggets he and his boss, John Sutter, attempted to keep the discovery a secret. However, word soon spread and by 1849 thousands of prospectors, who became known as 49ers, were flocking to Coloma, California, site of Sutter’s Mill, and the surrounding region, hoping to strike it rich.

The 49ers, most of whom were men, came from the eastern United States as well as other parts of the globe, including Europe, China, Mexico and South America.

By the mid-1850s, more than 300,000 people had poured into California. (In San Francisco alone, the city’s population soared from a thousand residents in 1848 to 20,000 citizens just two years later.) This huge influx of new arrivals helped speed up California’s admittance to the Union as the 31st state in 1850, a mere two years after the U.S. had been awarded the territory under the Treaty of Guadalupe-Hidalgo, which ended the Mexican-American War.

Of all those who came to California, some 49ers grew wealthy but it was the merchants—those that sold goods and services to the gold seekers—who typically made more money than the miners. In fact, James Marshall and John Sutter, the two men linked with the start of one of the most pivotal events in California history, never got rich.

A century after the Gold Rush, the 49ers were memorialized when San Francisco’s first major league professional sports franchise, a football team, was named.

The team, which started out as part of the All-America Football Conference (AAFC), a rival to the National Football League (NFL), played its first regular-season game in September 1946. When the AAFC folded three years later, the 49ers joined the NFL in 1950. In 1995, the San Francisco 49ers became the first NFL team to win five Super Bowls.