There are 51 US Post Offices in Tarrant County serving a total of 1,313,667 residents equating to 25,758 residents per post office. It's estimated that approximately 2,096,759 packages are handled across the 51 county post offices annually. Tarrant County is a county located in the U.S. state of Texas. As of the 2010 census, it had a population of 1,809,034. It is the third-most populous county in Texas and the sixteenth-most populous in the United States. Its county seat is Fort Worth. Tarrant County, one of 26 counties created out of the Peters Colony, was established in 1849 and organized the next year. The county was named in honor of General Edward H. Tarrant of the Republic of Texas militia. Tarrant County is part of the Dallas\u2013Fort Worth\u2013Arlington, TX Metropolitan Statistical Area."