The United States of America is a federal republic and a highly developed country with 50 states covering a vast swath of North America, with Alaska in the northwest and Hawaii extending the nation’s presence into the Pacific Ocean. Major Atlantic Coast cities are New York, a global finance and culture center, and capital Washington, DC. Midwestern metropolis Chicago is known for influential architecture and on the west coast, Los Angeles' Hollywood is famed for filmmaking.
The United States is the world's largest economy by nominal GDP, the second-largest by purchasing power parity, and accounts for approximately a quarter of global GDP. The United States is the world's largest importer and the second-largest exporter of goods. Although its population is 4% of the world total, it holds 31% of the total wealth in the world, the largest share of global wealth concentrated in a single country.
Despite income and wealth disparities, the United States continues to rank very high in measures of socioeconomic performance, including average wage, median income, median wealth, human development, per capita GDP, and worker productivity. It is the foremost military power in the world, making up a third of global military spending and is a leading political, cultural, and scientific force internationally.