Jacksonville, Fla, is located in Duval County and serves as the county seat. As of 2014, Jacksonville has the largest land area of any city in the mainland United States.
In 1968 the city and county governments merged into one single entity. As a result, Jacksonville includes most of Duval county. Jacksonville is considered the primary city in the greater Jacksonville metropolitan area. Located on the Atlantic coast in the northeast area of the state, Jacksonville sits on the St. Johns River, close to the Georgia state border. The history of Jacksonville spans hundreds of years. The original settlement that became Jacksonville was founded in 1791.