In spring and possibly through summer 1864, three blockhouses were constructed to help defend the town and post of Fort Scott. These were Fort Blair, Fort Henning and Fort Insley. Fort Blair was enclosed by a rectangular wall of log palisades covered on the outside by earthworks, which in turn were surrounded by a wide, deep ditch. These were to be used by armed men and cannon in case the town and post were attacked by Confederate guerrillas or regular forces.