Humanities › Geography Geography of the United States of America Share Flipboard Email Print moodboard/Getty Images Geography Country Information Basics Physical Geography Political Geography Population Key Figures & Milestones Maps Urban Geography By Amanda Briney Geography Expert M.A., Geography, California State University - East Bay B.A., English and Geography, California State University - Sacramento Amanda Briney, M.A., is a professional geographer. She holds a Certificate of Advanced Study in Geographic Information Systems (GIS) from California State University. our editorial process Amanda Briney Updated October 14, 2019 The United States of America is the third-largest country in the world based on population and land area. The United States also has the world's largest economy and is one of the most influential nations in the world. Fast Facts: United States Official Name: United States of AmericaCapital: Washington, D.C.Population: 329,256,465 (2018)Official Language: None, but most of the country is English-speaking Currency: US dollar (USD)Form of Government: Constitutional federal republicClimate: Mostly temperate, but tropical in Hawaii and Florida, arctic in Alaska, semiarid in the great plains west of the Mississippi River, and arid in the Great Basin of the southwest; low winter temperatures in the northwest are ameliorated occasionally in January and February by warm chinook winds from the eastern slopes of the Rocky MountainsTotal Area: 3,796,725 square miles (9,833,517 square kilometers)Highest Point: Denali at 20,308 feet (6,190 meters) Lowest Point: Death Valley at -282 feet (-86 meters) Independence and Modern History The original 13 colonies of the United States were formed in 1732. Each of these had local governments and their populations grew quickly throughout the mid-1700s. During this time, tensions between the American colonies and the British government began to rise, as the American colonists were subject to British taxation without representation in the British Parliament. These tensions eventually led to the American Revolution, which was fought from 1775-1781. On July 4, 1776, the colonies adopted the Declaration of Independence. Following the American victory over the British in the war, the U.S. was recognized as independent of England. In 1788, the U.S. Constitution was adopted and in 1789, the first president George Washington took office. Following its independence, the U.S. grew rapidly. The Louisiana Purchase in 1803 nearly doubled the nation's size. The early to mid-1800s also saw growth on the west coast, as the California Gold Rush of 1848-1849 spurred western migration and the Oregon Treaty of 1846 gave the U.S. control of the Pacific Northwest. Despite its growth, the U.S. also had severe racial tensions in the mid-1800s as enslaved Africans were used as laborers in some states. Tensions between the states that practiced enslavement and those that did not led to the Civil War, and 11 states declared their secession from the union and formed the Confederate States of America in 1860. The Civil War lasted from 1861-1865. Ultimately, the Confederate States were defeated. Following the Civil War, racial tensions remained throughout the 20th century. Throughout the late 19th and early 20th centuries, the U.S. continued to grow and remained neutral at the beginning of World War I in 1914. It later joined the Allies in 1917. The 1920s were a time of economic growth in the U.S. and the country began to grow into a world power. In 1929, however, the Great Depression began and the economy suffered until World War II. The U.S. also remained neutral during this war, until Japan attacked Pearl Harbor in 1941, at which time the U.S. joined the Allies. Following WWII, the U.S. economy again began to improve. The Cold War followed shortly thereafter, as did the Korean War from 1950-1953 and the Vietnam War from 1964-1975. Following these wars, the U.S. economy, for the most part, grew industrially and the nation became a world superpower concerned with its domestic affairs because public support had wavered during previous wars. On Sept. 11, 2001, the U.S. was subject to terrorist attacks on the World Trade Center in New York City and the Pentagon in Washington, D.C., which led to the government pursuing a policy of reworking world governments, particularly those in the Middle East. Government The U.S. government is a representative democracy with two legislative bodies, the Senate and the House of Representatives. The Senate consists of 100 seats, with two representatives from each of the 50 states. The House of Representatives consists of 435 seats, the occupants of which are elected by the people from each of the 50 states. The executive branch consists of the president, who is also the head of government and chief of state. The U.S. also has a judicial branch of government that is made up of the Supreme Court, the U.S. Court of Appeals, U.S. District Courts, and State and County Courts. The U.S. is comprised of 50 states and one district (Washington, D.C.). Economics and Land Use The U.S. has the largest and most technologically advanced economy in the world. It mainly consists of the industrial and service sectors. The main industries include petroleum, steel, motor vehicles, aerospace, telecommunications, chemicals, electronics, food processing, consumer goods, lumber, and mining. Agricultural production, though only a small part of the economy, includes wheat, corn, other grains, fruits, vegetables, cotton, beef, pork, poultry, dairy products, fish, and forest products. Geography and Climate The U.S. borders both the North Atlantic and North Pacific Oceans and is bordered by Canada and Mexico. It is the third-largest country in the world by area and has a varied topography. The eastern regions consist of hills and low mountains, while the central interior is a vast plain (called the Great Plains region). The west has high rugged mountain ranges (some of which are volcanic in the Pacific Northwest). Alaska also features rugged mountains as well as river valleys. Hawaii's landscape varies but is dominated by volcanic topography. Like its topography, the climate of the U.S. also varies depending on location. It is considered mostly temperate but is tropical in Hawaii and Florida, arctic in Alaska, semiarid in the plains west of the Mississippi River and arid in the Great Basin of the southwest. Sources "United States." The World Factbook, Central Intelligence Agency. "United States Profile." Countries of the World, Infoplease.