Culper Substitution Cipher

Why Is It Called “Culper”?

During the American Revolution, General George Washington needed spies to help him learn what the British Army was doing. But spies had to stay hidden—if they were caught, they could be in big trouble! To protect them, Washington and his spymaster, Benjamin Tallmadge, gave the spies secret code names.

One of the main spies was a farmer named Abraham Woodhull, and his secret name was “Samuel Culper.” Tallmadge picked the name from Culpeper County, Virginia, a place he knew well. Later, another spy named Robert Townsend became “Culper Junior.” Together, they led a whole team of undercover agents known as the Culper Spy Ring.

So when you hear about Culper codes or Culper ciphers, it simply means the secret messages and tricks used by these brave spies to help America win its freedom!