 liberty is a city in the u.s. state of texas, within  metropolitan area. the population was 8,397 at the 2010 census. it serves as the seat of liberty&nbsp;county. liberty is the third oldest city in the stateâestablished in 1831 on the banks of the trinity river. the city also has a twin of the liberty bell from philadelphia, pennsylvania. its area code is 936 and its zip code is 77575. ==history==  liberty, texas is the county seat of liberty and the third oldest town in texas. texas heroes william b. travis, sam houston, and david burnet all practiced law in liberty. three brothers from liberty died at the alamo, while some 50 liberty citizens fought in the battle of san jacinto in 1836 when texas won its independence. liberty is located onu.s. highway 90 in the south central 
Cities_in_Liberty_County,_Texas Cities_in_Texas County_seats_in_Texas Greater_Houston