Constructed by the Union Army in the summer of 1862 and expanded in 1864 using soldiers and freed slaves, Fort Harker stood on a broad hill a quarter mile east of town, overlooking Crow Creek and lying well within firing range of Stevenson's strategic railroad lines, supply depots, and warehouses. It was an earthen redoubt, 150 feet square, with walls 14 feet high, surrounded by an 8 foot deep dry moat, and it contained 7 cannon platforms, a bomb-proof powder magazine, a drawbridge entrance, and an 8-sided wooden blockhouse at its center. Soldiers building the fort reported that the soil was very hard and required the continual use of a pick, yet the work remained critical to Union plans, and the officer in charge was ordered to work night and day to complete it as rapidly as possible. Along the railroad lines at Stevenson during the Civil War, one other large fort, two smaller redoubts, and at least seven blockhouses were also constructed. No major fighting occurred here, but skirmishes and sniper attacks were common as territory traded hands between Union and Confederate forces.