Oakdale was first called Bay. It had a Post Office by the name of Bay approximately two miles southwest of the present town site. William T. Dunn was the first Postmaster at Bay and had a grist mill, cotton gin and sawmill. May 4, 1885 Dunn was given a patent by the US Government for 160 acres of land on which 80 acres of present Oakdale is now located. Dunn donated the 80 acres for Oakdale's town site and following that donation, the town changed its name to Dunnsville. While still a part of Calcasieu Parish, Dunnsville became Oakdale because a team of surveyors were impressed with the live oaks that were on the present site of the town. The Oakdale Post Office was established Jan 21, 1911. Allen Parish was created out of Calcasieu Parish in 1912.