1940- Jeff Davis Parish was created in 1912 by dividing Imperial Calcasieu Parish into four parts, Jeff Davis being one of the parts. The parish was settled by a large number of people from Mid-Western States of Iowa, Illinois, Ohio, Tennessee, Kentucky and others. In addition to this, French settlers from the eastern part of Louisiana moved westward and settled along the streams of the Parish.
Jennings, the county seat, is one of the oldest towns in the Parish.