Frequently, part of our most cherished cultural landscapes, the National Park Service is working to increase the odds of their survival. Earthworks, also known as fieldworks or earthen fortifications, have been used throughout American military history as a form of defense. Many cultures, including those of Native Americans, have used forms of fortifications for thousands of years. However, the development of fortifications used in the United States during the eighteenth and nineteenth centuries, is European in origin. The basic function of earthworks is relatively simple, to place a barrier between yourself and the enemy.
Most earthen fortifications consist of two basic parts.
The first part is a wall of earth, generally refered to as a parapet. Besides earth, a parapet could also contain wood or stone, which added strength and stability to the form. The second of these two basic parts is the ditch or trench. This provided the necessary soil for the parapet. Many more featues could also be added to provide additional protection, to allow special placements for artillery, or to create additional obstacles for enemy troops.