Texas is a state in the South Central United States, nicknamed the Lone Star State. Texas is the second largest U.S. state in both area and population, with an area of 268,820 square miles (696,200 km²), and with a growing population of 24.6 million residents. Houston is the largest city in Texas and the fourth-largest in the United States, while the Dallas–Fort Worth Metroplex is the largest metropolitan area in the state and the fourth-largest in the nation.