The United States emerged as an independent nation in 1776 when thirteen British colonies declared their separation from Great Britain, a status formally recognized in the 1783 Treaty of Paris. Over the next two centuries, the country expanded westward across the North American continent, ultimately forming a union of 50 states and acquiring several overseas territories. The nation endured defining trials, including the Civil War of 1861–65—when the Union defeated the secessionist Confederacy—and the Great Depression of the 1930s, during which roughly one-quarter of the labor force was unemployed.
Victories in both World Wars and the conclusion of the Cold War in 1991 cemented the United States as the world’s most powerful nation-state. Since World War II, the country has experienced sustained economic growth, low unemployment, and rapid technological advancement.
National anthem
"The Star-Spangled Banner"
adopted 1931; during the War of 1812, Francis Scott KEY witnessed the successful American defense of Baltimore's Fort McHenry against a British naval bombardment, later writing a poem about it that would become the US national anthem; the lyrics were set to the tune of "The Anacreontic Song;" there are four verses, but only the first verse is sung
