The land that became the United States was inhabited by Native Americans for tens of thousands of years, with their descendants including 575 federally recognized tribes. European colonization began in the late 15th century, largely decimating Indigenous societies through wars and epidemics. English settlement took hold with the founding of Jamestown in 1607 and the Mayflower landing at Plymouth in 1620.
Following Britain's victory over France in the French and Indian Wars, Parliament imposed taxes and the Intolerable Acts of 1773, triggering a colonial crisis. Tensions escalated into the Revolutionary War, which began at the Battles of Lexington and Concord on April 19, 1775. The Second Continental Congress established the Continental Army under George Washington, and on July 4, 1776, declared independence. Britain formally acknowledged American sovereignty in the Treaty of Paris on September 3, 1783. The U.S. Constitution was signed in 1787, ratified in 1789 — now the world's oldest written national constitution — and supplemented by the Bill of Rights in 1791.
Washington became the first president in 1789. His Treasury Secretary Alexander Hamilton advocated for a strong central government, in contrast to Thomas Jefferson and James Madison. In 1803, President Jefferson negotiated the Louisiana Purchase, doubling the country's size. Westward expansion followed under the banner of manifest destiny, marked by conflicts with Indigenous peoples. President James K. Polk annexed Texas in 1845, declared war on Mexico the following year, and the resulting Treaty of Guadalupe Hidalgo in 1848 handed the U.S. much of the American Southwest.
The question of slavery in new territories drove deepening national conflict. Following Abraham Lincoln's election as the 16th president in 1860, southern states seceded and formed the Confederate States of America. The Civil War began at Fort Sumter in April 1861. The Union's pivotal victory at Gettysburg — the war's deadliest battle with over 50,000 casualties — turned the tide, and the Union prevailed in 1865. Lincoln was assassinated on April 15 of that year. The Confederacy's defeat ended slavery. The Reconstruction era (1865–1877) sought to protect individual rights, but white southern Democrats regained power in 1877, enforcing white supremacy through Jim Crow laws and voter suppression.
During the Gilded Age of the late 19th and early 20th centuries, the U.S. emerged as the world's leading industrial power, driven by ent
