Dr Church's Cypher Letter to John Fleeming

   Below is the original Church cypher letter, with envelope. The original is in the George Washington Papers at the Library of Congress. Access to the original letter is now restricted; however, I was able to handle this letter over 25 years ago before access, necessarily, was restricted by the Library.

   Below is a readable copy of the original cipher letter:

   Church used what is referred to in cryptography as a "monoalphabetic cipher" in his letter to John Fleeming, his brother-in-law -  a simple substitution code that uses fixed substitution over the entire message as opposed to a "polyalphabetic cipher" that uses a number of substitutions at different times. Here is the key to Dr Church 's cipher:

The top line is the alphabet. The second line sets forth the substitutions in Church's handwriting. The third line is the legible version of the second line.

   Using the key, we get the first two sentences of the letter:

      I hope this will reach you. Three attempts have I made without success in effecting the last.

   Those interested in the use of ciphers in correspondence in Colonial America may wish to read my blog post on that subject.

https://drbenjaminchurchjr.blogspot.com/2011/05/use-of-ciphers-in-colonial-america.html