The Female Spy Who Aided the War

During the American Revolution, information was as valuable as ammunition. In the British-occupied territory of Long Island, a secret group known as the Culper Spy Ring operated under the direct orders of General George Washington.

Anna Smith Strong lived on Strong’s Neck in Setauket, New York, a strategic location overlooking the Long Island Sound. According to local history, Anna played a vital role as a visual communicator. She allegedly used her laundry line as a signaling system for the ring’s courier

The ring courier's name was Caleb Brewster. By hanging a black petticoat and a specific number of white handkerchiefs, she could signal which hidden cove Brewster should use to land his boat and collect secret dispatches.

The spies used a sophisticated system of invisible ink and a complex "dictionary" where numbers replaced common words. In this system, the number 355 stood for "Lady."

In a 1779 letter to Washington, the lead spy Abraham Woodhull mentioned an operative who was "acquainted with 355," suggesting that a woman with high-level social access was providing critical intelligence from within British-occupied New York City.

While many believe Anna Smith Strong was Agent 355, historians are divided. Some suggest that 355 was a different woman—perhaps a member of a prominent Loyalist family who secretly supported the Patriot cause.

Others believe that "355" was simply a general term for any female informant. However, Anna’s documented proximity to the ring and her family's connections to the other spies make her the most enduring candidate for this legendary role.

The intelligence gathered by the Culper Ring was instrumental in the American victory. They uncovered the treason of Benedict Arnold and warned Washington of British plans to attack French reinforcements.

Whether Anna Smith Strong was officially Agent 355 or simply a brave neighbor aiding the cause, her contributions—and the work of other "invisible" women—were essential to the birth of the United States.