kitchen wing was added to the officers' quarters building. American Civil War During the Civil War the Union used Fort Mifflin to house Confederate prisoners of war, as well as Union soldiers and civilian prisoners. Numerous Confederate prisoners occupied Fort Mifflin from 1863 to 1865 and were housed in Casemate #1. The Union Army used three smaller casemates to hold political prisoners during the same period. Various people wrote graffiti inside the cell doors and on the inner walls of "Casement #11" during the 1860s. They also left a wine token and penny, both dated 1864 and in remarkable condition. The Union Army accused William H. Howe, one of its soldiers, of desertion, found him guilty of murder, and imprisoned him famously at Fort Mifflin from January 1864. Howe led an attempted escape of two hundred prisoners from Casemate #5 in February 1864. Afterwards, Howe was housed in a solitary confinement cell in Casemate #11, where he left his signature. Despite his illiterate reputation, Howe twice wrote letters (filled with bad grammar and run-on sentences) to President Abraham Lincoln asking for clemency, signing them with his own hand. In April 1864 Howe was transferred to Eastern State Penitentiary but, on 26 August of the same year, was transferred back to Fort Mifflin. The condemned prisoner was briefly held in the fort's wooden guardhouse prior to his execution on the gallows, which were steps away from the guardhouse. Howe's hanging was before an audience of persons who paid for tickets to watch the execution. Of the three other men executed at Fort Mifflin, none had a paid public audience. The army proposed adding a sally port on the west side in 1864. On 24 November 1864, the Union Army sent Lieutenant Colonel Seth Eastman, the American Western frontier painter, to Fort Mifflin to supervise the discharge of all civilian and military prisoners, then numbering more than two hundred. On 2 January 1865, Eastman reported that his garrison consisted of B Company, 186th Pennsylvania Volunteer Regiment, a detachment of recruits, and the hospital staff. After the Civil War On 20 August 1865, Captain Thomas E. Merritt with A Company, 7th United States Veteran Volunteers, relieved Lieutenant Colonel Eastman. The army completed the west sally port by 1866. In 1866 the 7th USVV vacated the fort and the District Engineer Office, Corps of Engineers, replaced the company. The fort passed in and out