Gallia County was formed on March 25, 1803, from portions of Adams and Washington counties. Gallia County had originally been settled by French immigrants, who named the county “Gallia,” the Latin name for Gaul, which is corresponding to present day Belgium and the present day France. History states that in 1818, a group of immigrants from Wales settled in the county making the second most common language. The county has a total area of 471 square miles and a population count of 29,898 residents.