Houston is the fourth-largest city in the United States of America and the largest city in the state of Texas. According to the 2010 U.S. Census the city had a population of 2.1 million people within an area of 579 square miles (1 500 km). Houston is the seat of Harris County and the economic center of Houston–Sugar Land–Baytown which is the sixth-largest metropolitan area in the U.S. of nearly 6 million people. Houston was founded in 1836 on land near the banks of Buffalo Bayou.