In 1896, legislative work began to create what was to be known as Jefferson Davis Parish. It was not until fourteen years after the initial work began that the parish was established. Prior to January 1, 1913, the territory now called Jefferson Davis Parish was, along with Allen and Beauregard Parishes, part of the “Imperial Calcasieu Parish”. Named after the President of the Confederacy, Jefferson Davis Parish was formed on June 12, 1912, when Governor L.E. Hall signed the Parish Division Bill. The “Imperial Calcasieu Parish” was divided - separating Calcasieu and creating Jefferson Davis Parish. On October 22, 1912, Jennings was selected as the permanent parish seat.
Jefferson Davis Parish lies in the Third District of the State Supreme Court and in the Third Circuit Courts of Appeal. It is in the Thirty-First Judicial District, which began its existence on March 16, 1953, and is composed of Jefferson Davis Parish.