United States Military Telegraph--Archives United States. Army of the Potomac--Archives United States. Military Telegraph Corps United States. War Department--Correspondence United States--History--Civil War, 1861-1865--Communications--Sources
Thomas T. Eckert papers, 1861-1877 (bulk 1862-1867) Thomas T. Eckert Papers, Decoding the Civil War
Purchased in part by the Library Collectors' Council from Seth Kaller, January 21, 2012.