Anna "Nancy" Strong was a member of the Culper Spy Ring in Setauket NY during the American Revolution. This small group of Continental supporters gathered information in New York City and passed it to an agent. He carried it to Setauket and placed it into a drop-box on a farm.
Mrs. Smith lived within view of the farm and used her laundry as a code to indicate when the information could be delivered to the next agent. When Agent 725 a whaler was hidden in one of six local coves Mrs. Smith would hang her black petticoat on her clothesline. She indicated which of the six coves by hanging up handkerchiefs along with the black petticoat. No one knows how Mrs. Smith knew when and where Agent 725 was hiding.