America, formerly inhabited by indigenous Americans, was colonized by the British in the early 1600s and was subsequently the first of the British colonies to gain independence. The country declared independence in 1776 and won the Revolutionary War, establishing a democratic republic. The Civil War (1861-1865) abolished slavery, and the country underwent swift growth in the 18th century transformed by rapid Industrialization and urbanization. The US played a crucial role in both World Wars, emerging as a superpower. The Cold War was a significant event in the late 1990s which shaped US foreign policy, until the Soviet Union's collapse in 1991. Mass global immigration, which commenced in the 19th century, has led to the diversity that characterizes modern society in the US.
The US functions as a federal republic of 50 states and is the third most populous country in the world. The constitution, ratified in 1788, separates the powers between the three branches of government: legislative, executive, and judicial, with the President serving as the head of the national government. Power is shared between a central national government and individual state governments, with laws diverging by jurisdiction. The American political party system consists of two major parties, Democrats and Republicans.
The American economy accounts for one fourth of global GDP. The economy has faced downturns, including the Great Depression in the 1930s and the Global Financial Crisis in 2007-08, but has maintained its status as one of the most advanced economies in the world. The services sector contributes close to 80% of the US GDP, with the manufacturing sector representing 11-12% of GDP. The Federal Reserve plays a crucial role in monetary policy, and as the world's largest economy, the country’s economic decisions impact international markets, currencies, and financial stability. While the economy's strength lies in its adaptability, it faces challenges in income inequality, trade imbalances, and ongoing geopolitical dynamics.
