Confederacy, Charleston "Union 600" (Roper Hospital), blue cover endorsed "From Prisoner of War, Charleston S.C." and original enclosed letter datelined "Military Prison Charleston S.C., Oct 4th 1864", manuscript "Exd" and additional red manuscript "Soldiers Letter, W. I. Bennett, Lt col & Agt - Ex, DS" examiner's marking, entered mails with "Port Royal S.C. Nov 13 1864" cds and matching "Due 3" rating; small edge tear and some tone spots, Very Fine. Estimate  $1,500 - 2,000. A SCARCE PRISONER-OF-WAR COVER FROM A UNION OFFICER ON THE CONFEDERATE SIDE OF THE INFAMOUS "600" STALEMATE. Original letter mentions, "I have not written to you for several months. partly because the mails have been so irregular that I feared letters would not reach you, and partly waiting in hopes to hear from you. We have received no regular mail now for four months, but now communication is reestablished. Since leaving Richmond I have been at Macon and Savannah Ga. and but recently arrived here…"There are many interesting stories of prisons and one of the most interesting is that of three Southern locations where captured Confederate officers were held by Federal forces, right in the bosom of the Confederacy itself. These three prisons were Morris Island in Charleston Harbor, SC, Hilton Head in the harbor of Port Royal, SC, and Fort Pulaski near Savannah, GA. All are interconnected with the plight of 600 Confederate officer prisoners known in Southern history as "The Immortal 600."The story begins in June 1864 when the Confederates placed 50 high-ranking Union officer prisoners in Charleston where the Union believed they would be subject to Union artillery fire from Morris Island. The North promptly sent a similar number of Confederate officers to Morris Island to be exposed to Confederate artillery. On August 3, 1864, both sides exchanged these prisoners. Then the Confederates transferred 600 more prisoners to Charleston. On August 20, 1864, the Union retaliated by shipping 600 prisoners from Fort Delaware to Morris Island near Charleston, arriving on September 7. They were held in open barracks as "human shields" under direct shelling from Confederate forces in retaliation for Union prisoners being held in Charleston under shelling from U.S. forces. General Grant vetoed another prisoner exchange, however, the stalemate was broken when the Union prisoners were moved from Charleston because of an outbreak of yellow fever. $0 (Image)