The remains of these breastworks once supported a Gatling gun and a small group of infantry at the Fort Abraham Lincoln Infantry Post, covering the western and northwestern approaches to the post. The Gatling gun was a rapid-fire weapon capable of delivering the firepower of an entire infantry company. First seeing action during the Civil War, its design was brought west after the war. Mechanical reliability and mobility problems plagued the weapon, limiting its offensive value. Although these guns were available in several calibers, the Gatling guns at Fort Abraham Lincoln appear to have been 1.0 and .50 caliber, one inch and one-half inch respectively.