 About 9.3% of families and 11.8% of the population were below the poverty line, including 13.1% of those under age 18 and 17.4% of those age 65 or over.Federal Correctional Institution, Seagoville is located in Seagoville.The United States Postal Service operates the Seagoville Post Office on Seagoville Road in Kleberg, Dallas.