Paleo-Indians moved from Eurasia to what is currently the U.S. terrain no less than 15,000 years ago, with European colonization starting in the sixteenth century. The United States rose up out of 13 British settlements along the East Coast. Question between Great Britain and the states prompted the American Revolution. On July 4, 1776, as the settlements were battling Great Britain in the American Revolutionary War, delegates from the 13 provinces collectively received the Declaration of Independence. The war finished in 1783 with acknowledgment of the freedom of the United States by the Kingdom of Great Britain, and was the main effective war of autonomy against an European provincial empire.The nation's constitution was embraced on September 17, 1787, and endorsed by the states in 1788. The initial ten corrections, on the whole named the Bill of Rights, were approved in 1791 and intended to ensure numerous basic common freedoms.
Driven by the regulation of Manifest Destiny, the United States set out on a fiery extension crosswise over North America all through the nineteenth century. This included uprooting American Indian tribes, obtaining new regions, and progressively conceding new states, until by 1848 the country spread over the mainland. Amid the second 50% of the nineteenth century, the American Civil War finished legitimate servitude in the nation. Before that century's over, the United States stretched out into the Pacific Ocean, and its economy, driven in huge part by the Industrial Revolution, started to soar.The Spanish–American War and World War I affirmed the nation's status as a worldwide military force. The United States rose up out of World War II as a worldwide superpower, the principal nation to create atomic weapons, the main nation to utilize them in fighting, and a perpetual individual from the United Nations Security Council. The end of the Cold War and the disintegration of the Soviet Union in 1991 left the United States as the world's sole superpower.
The United States is a created nation and has the world's biggest national economy by ostensible and genuine GDP, profiting from a plenitude of normal assets and high specialist profitability. While the U.S. economy is considered post-modern, the nation keeps on being one of the world's biggest makers. Representing 34% of worldwide military spendin and 23% of world GDP, it is the world's preeminent military and financial force, a noticeable political and social power, and a pioneer in logical exploration and mechanical developments.