1. Culper Spy Ring - Revolutionary War
... would appear invisible on the paper of the letters; this is how they established the name "invisible ink." To put a bit more of a challenge on the art of cracking the code, they would write in between lines, at the end of the letter, or on the reverse side. To read the letter, the spies would hold the letter over ... ...
- Word Count: 1610
- Approx Pages: 6