Phoenix is the capital and largest city of the U.S. state of Arizona, as well as the fifth most populated city in the United States. Phoenix is home to approximately 1.5 million people, and is the anchor of the Phoenix metropolitan area (also known as the Valley of the Sun), the 12th largest metro area by population in the United States with nearly 4.3 million people. In addition, Phoenix is the county seat of Maricopa County, and is one of the largest cities in the United States by land area. Phoenix was incorporated as a city in 1881 after being founded in 1868 near the Salt River, near its confluence with the Gila River. The city eventually became a major transportation hub in North America and a main transportation, financial, industrial, cultural and economic center of the Southwestern United States. The city has a notable and famous political culture and has been home to numerous influential American politicians and other dignitaries, including Barry Goldwater, William Rehnquist, John McCain, Janet Napolitano, Carl Hayden, and Sandra Day O'Connor. Residents of the city are known as Phoenicians. Located in the northeastern reaches of the Sonoran Desert, Phoenix has the hottest climate of any major city in the United States. The average high temperatures are over 100°F (37.8°C) for three months out of the year, and have spiked over 120°F (48.9°C) on occasion.