Overview of Civil War Codes and Ciphers

Union Army Cipher Disk- American Civil War flag telegraphy

ciphers Decoding the Civil War

The Secret History of the Civil War: The Thomas T. Eckert Archive of Civil War Codes and Ciphers (SOLD)

John Wilkes Booth's “Confederate” Cipher

Secret Codes and the Founding Fathers

History of Codes and Ciphers in the United States Prior to World War One (Cryptographic Series): United States Army Security Agency Historical Section, Barker, Wayne G.: 9780894120268: : Books

The Secret History of the Civil War: The Thomas T. Eckert Archive of Civil War Codes and Ciphers (SOLD)

Development of Stager Ciphers during the Civil War

Woods, Ciphers, and Stones

Civil War at the National Cryptologic Museum on Virmuze

Mathematics and Primary Sources: Historic Codes, Ciphers, and Computational Thinking, Part I

Overview of Civil War Codes and Ciphers

The Birth and Evolution of Cryptographic Codes - Probabilistic World