During the Plains Indian Wars, especially following the Civil War, The US Army used companies of skirmishers ahead of the main force. The recommended distance between them was but most commanders simply kept skirmishers within sight of each other. They were used mainly ahead of the main force but could be used to defend the flanks or as a rearguard. If the Indians attacked, the skirmisher company formed a defensive circle. Once the danger had passed, they returned to their original positions. Often, the entire company was not deployed as skirmishers. Some were kept in reserve to fill gaps, to get ammunition or to carry messages. 