The Martyrs Monument of Midway, Ky., honors four Confederates publicly executed by the Union one hundred fifty years ago today. A brutally contested frontier zone between North and South, Kentucky at this point was under martial law, governed by General Stephen Burbridge — but nearly anarchic on the ground in some areas. In an effort to quell the activities of Confederate guerrillas-slash-outlaws, Burbridge issued a still-notorious directive called Order 59: Citing the “rapid increase in this district of lawless bands of armed men,” the order threatened to expel Southern sympathizers and seize their property. Moreover, it warned: “Whenever an unarmed...