Overview of Civil War Codes and Ciphers

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)

John Wilkes Booth's “Confederate” Cipher

Codes & Ciphers – Don Wyman Presents

American Civil War for Kids - Codes and Ciphers

World War I cryptography - Wikipedia

Civil War Puzzle Station Activity - Abraham Lincoln

File:Civil War cipher disk.jpg - Wikipedia

Civil War Cipher Disks