Stain the intended intelligence." Even though the Patriots took great care to write sensitive messages in invisible ink, or code or cipher, it is estimated that the British intercepted and decrypted over half of America's secret correspondence during the war. Codes and ciphers American Revolutionary leaders used various methods of cryptography to conceal diplomatic, military, and personal messages. John Jay and Arthur Lee devised dictionary codes in which numbers referred to the page and line in an agreed-upon dictionary edition where the plaintext (unencrypted message) could be found. In 1775, Charles Dumas designed the first diplomatic cipher that the Continental Congress and Benjamin Franklin used to communicate with agents and ministers in Europe. Dumas's system substituted numbers for letters in the order in which they appeared in a preselected paragraph of French prose containing 682 symbols. This method was more secure than the standard alphanumeric substitution system, in which a through z are replaced with 1 through 26 because each letter in the plain text could be replaced with more than one number. The Culper Spy Ring used a numerical substitution code developed by Major Benjamin Tallmadge, the network's leader. The Ring began using the code after the British captured some papers indicating that some Americans around New York were using "sympathetic stain." Tallmadge took several hundred words from a dictionary and several dozen names of people or places and assigned each a number from 1 to 763. For example, 38 meant to attack, 192 stood for the fort, George Washington was identified as 711, and New York was replaced by 727. An American agent posing as a deliveryman transmitted the messages to other members of the Ring. One of them, Anna Strong (spy), signaled the message's location with a code involving laundry hung out to dry. A black petticoat indicated that a message was ready to be picked up, and the number of handkerchiefs identified the cove on Long Island Sound where the agents would meet. By the end of the war, several prominent Americans—among them Robert Morris, John Jay, Robert Livingston, and John Adams—were using other versions of numerical substitution codes. The Patriots had two notable successes in breaking British ciphers. In 1775, Elbridge Gerry and the team of Elisha Porter and the Rev. Samuel West, working separately at Washington's direction, decrypted a letter that implicated Dr. Benjamin Church, the Continental Army's chief surgeon, in espionage for the