Northern prisoners, especially conscripted recent immigrants, had time to reconsider where their loyalties lay while awaiting exchange. William Irwin of Maine and 1700 others decided to enlist in the Eighth Confederate Battalion (formerly the Second Foreign Battalion) while imprisoned at Salisbury Prison in North Carolina. After the prison was overrun by Northern forces in April 1865, Irwin saw it wise to reestablish his spoken loyalty to Lincoln’s government.
Bernhard Thuersam, www.Circa1865.org
“As early as 1862 Union prisoners were joining the Confederate forces. This process continued with varying intensity throughout the war but saw its greatest results toward the end.
On 21 August 1864 the adjutant and inspector general issued General Order 65, which spelled out a new policy of encouraging enemy prisoners, particularly aliens, and most particularly Irish Catholics, to enlist with Confederate forces. In late 1864 Colonel Zebulon York established a camp about three miles west of the prison at Salisbury to which prisoners enlisting were taken to be trained and organized into Confederate units.
After the war the U.S. government compiled a list of prisoners who had sworn allegiance to the Confederacy based on the records of Salisbury prison . . . [and] the list contains some two thousand names. Most of the men were of Irish extraction.
Of 2,072 names on the list believed to be unique, nearly half (48 percent) were from units recruited in New York. The next largest was from Pennsylvania (15 percent), followed by Massachusetts (9 percent), the border States (6 percent), New Hampshire (4 percent), the regular army (4 percent), with the remaining 13 percent coming from twelve other States, including the District of Columbia.
[Colonel York’s] “Galvanized Yankees,” as they were called, gave a good account of themselves in defending the Yadkin /river bridge against General George Stoneman’s cavalry in April 1865. In summary, it would appear that the Confederate handling of prisoners of war deprived the Union of several thousand soldiers and made a modest addition to Confederate manpower.
There is no way of knowing how many Union prisoners agreed to serve as Confederate agents on their return north [when officially exchanged], but undoubtedly some did. In addition to direct recruitment, the Confederacy also exploited the exchanges to plant its own agents under assumed identities.”
(Come Retribution, the Confederate Secret Service and the Assassination of Lincoln, William A. Tidwell, University of Mississippi Press, 1988, excerpts pp. 121-124)