Brownsville is the county seat of Cameron County, Texas, United States. It is the sixteenth-most populous city in the state of Texas, with a population at the 2010 census of 175,023 and an estimated population in 2014 of 183,046. Brownsville is located at the southernmost tip of Texas, on the northern bank of the Rio Grande, directly north and across the border from Matamoros, Tamaulipas, Mexico.The 2014 U.S. Census Bureau estimate placed the Brownsville-Harlingen metropolitan area population at 420,392, making it the ninth most populous metropolitan area in the state of Texas. In addition, the international Matamoros–Brownsville Metropolitan Area was estimated to have a population of 1,136,995.Brownsville has one of the highest poverty rates in the nation, and is frequently cited as having the highest percentage of residents in the nation below the federal poverty level. But the urban area is also one of the fastest growing in the United States.