In retaliation for the executions in mid-May 1863 of two Confederate officers, the commander of the Libby Prison in Richmond, Captain Thomas Turner, was ordered to select for hanging  two Union prisoners of equal rank.  Captains Henry W. Sawyer of New Jersey and John Flinn of Indiana were chosen by lot and promised execution in fourteen days time.  Federal authorities countered, selecting two of their own prisoners, one a son of Robert E. Lee, to be hanged immediately after the deaths of Sawyer and Flinn. Neither threat was carried out.  (By John Osborne)

The month before, Confederate Captains William F. Corbin and T.G. McGraw had been arrested in Pendleton County, Kentucky.  In his typical style, General Ambrose Burnside, commanding the Department of the Ohio, quickly convicted the two of spying and recruiting for the Confederacy.  They were held and then executed at the giant Johnson's Island prison camp near Sandusky, Ohio. This was a sensitive time for the treatment of prisoners and the deaths resulted in a serious Confederate threat of retaliation in early July, 1863.  (By John Osborne)