McAllen is the twenty-first most populous city in Texas and the largest city in Hidalgo County, Texas, United States. It is located at the southern tip of Texas in the Rio Grande Valley and is part of the Southern United States. It is on the Rio Grande, across from the Mexican city of Reynosa, and is approximately 70 miles (110 km) west of South Padre Island and the Gulf of Mexico. The 2010 United States census put the city's population at 129,877 and the McAllen-Edinburg-Mission metropolitan area at 774,773. It is ranked the fifth most populated metropolitan area in the state of Texas. The Reynosa-McAllen Metropolitan Area counts a population of nearly 1.5 million.From its settlement in 1904, the area around McAllen was largely rural and agricultural in character, but the latter half of the 20th century saw steady growth, which accelerated during the 1980s, leading to an economic and population boom in the 1990s and 2000s. Today, the McAllen-Edinburg-Mission metropolitan area is one of the fastest growing metropolitan areas in the United States. The introduction of the maquiladora economy and the North American Free Trade Association led to a boom in international trade, cross-border commerce with Mexico, and health care.