Civil War Earthworks. One of two lines of fortifications excavated from January to March 1864 by Union forces "on fatigue duty" soon after their capture of Madisonville. Intended to defend the town from Confederate attacks coming from the surrounding countryside. The earthworks originally consisted of a trench protected by an "abatis" or barrier of felled trees with sharpened ends laid pointing out along its edge. The line meandered from approximately Rene and Covington Streets in a westerly direction to about this point on Johnson Street. Property records for the lot adjacent to this site mention "breastworks" on the land from the 1870s forward. Madisonville was occupied to obtain war supplies in the form of timber, lumber, logs, turpentine, tar and bricks for the federal Department of the Gulf.