In the early days of the United States, no one had to worry about hacked emails or data dumps from Wikileaks. In some ways, though, keeping state secrets secret may have been even more difficult then than it is now. Before emails and cell phones, all spies had to do was get their hands on a document, pass it along to their leaders, and the plans for revolution could be foiled. If the plans of the Founding Fathers had been intercepted, the United States might never have existed. And the Founders might have been executed for treason.
So the Founding Fathers tended to write in code.
Thomas Jefferson began playing around with codes when he was in college. Later he designed a mechanical device, called a wheel cipher, for encoding messages. George Washington was fond of using invisible ink in messages to spies who were working for him during the Revolution. The Founders continued to use codes even after the Revolution. In May of 1789, James Madison sent an encoded letter to Thomas Jefferson. It was a discussion of the Bill of Rights they were planning to add to the Constitution. Ben Franklin invented some codes that were used by the Continental Congress.
The Founders used several different kinds of codes and ciphers.* Substitution codes were common. Substitution codes replace the letters in a message with other letters. “Hello” might be written as “Pqrru,” replacing H with P, E with Q, the Ls with Rs, and the O with U.
Sometimes they used book codes. Book codes are fun and can be very difficult to break. Only the person sending and the person receiving the message know what book is the key to the code. Here’s an example of a book code I made using the book Harry Potter and the Prisoner of Azkaban. **
The first number in each set is a page number in the book. The second number tells you which word on that page you’re looking for. You count the words on that page until you get to the second number. This is the word you’re trying to decode. For example, in the first set of numbers, the page is 61, the fourth word on the page. The fourth word on page 61 is the first word of the message. ***
Codes and ciphers can be fun. But when used by people plotting a Revolution, they can be matters of life and death.
* There is a technical difference between a code and a cipher, but most people use the terms interchangeably.
** It’s important that the sender and the receiver have the same edition of the book. This code set is from the 1999 Scholastic hardback edition. (See, bibliographies really are important!)
*** Here’s the decoded message—in case you don’t have the right edition of the book: “How have you been?” Yeah, it’s a lame message, I know. But book ciphers are a pain to make. No wonder Jefferson invented a wheel cipher!
Ideas for activities and discussion:
What did the Founding Fathers risk if their letters were intercepted by the British?
What do you think would have happened if the colonies had lost the Revolutionary War?
Can you make up a code of your own? Can you think of a way to make a code that would be easy for your family to decode, but uncrackable by anyone outside your family?
Read more about Jefferson’s ciphers.