The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, 326 Indian reservations, and some minor possessions.[j] At 3.8 million square miles (9.8 million square kilometers), it is the world's third- or fourth-largest country by total area.[d] The United States shares significant land borders with Canada to the north and Mexico to the south, as well as limited maritime borders with the Bahamas, Cuba, and Russia.[22] With a population of more than 331 million people, it is the third most populous country in the world. The national capital is Washington, D.C., and the most populous city is New York City.

U.S.

The ________ forged a strong new cultural identity in the 1920s and 1930s, with the popularization of baseball and the growing international attraction of Hollywood and jazz.

US Constitution

In 1788, four years after achieving independence, the states ratified the ________, establishing a new federal government which remains in force today.

Space Race

The ________, another measure of U.S.- Soviet competition during the Cold War, resulted in the Apollo 11 mission that saw the United States land the first man on the Moon in 1969.

North America

In the early 19th century, the country began expanding across ________, gradually obtaining new territories, sometimes through war, frequently displacing Native Americans, and admitting new states; by 1848, the United States spanned the continent.

North American mainland

Paleo- Indians migrated from Siberia to the ________ at least 12, 000 years ago, and European colonization began in the 16th century.

21st century

In the ________, the United States has increasingly been challenged by China as a dominant superpower.

1861 1865

Slavery was legal in the southern states, which sparked the American Civil War (________)

Soviet Union

The dissolution of the ________ in 1991 ended the Cold War, leaving the United States as the world's sole superpower for the next two decades.

Constitution of Jad

It played a significant role in establishing the United Nations and drafting the 1947 ________ the Soviet Union faced growing tensions that escalated into the Cold War, which would play out for the duration of the 20th century.