An excerpt from Women of the American Revolution:
"Washington had begun intelligence efforts within a fortnight of gaining command of the Continental Army, writing, ‘There is nothing more necessary than good intelligence to frustrate a designing enemy, & nothing that requires greater pains to obtain.’ The Culper Ring was one of the most extensive spy networks of the American Revolution. It was composed of people that Tallmadge knew personally and trusted implicitly. Abraham Woodhull and Caleb Brewster had grown up in Setauket, New York with Tallmadge, and they formed the center of the ring. Initially, Woodhull went by the alias Samuel Culper. Later, Tallmadge assigned him the code number 722. Agent 355 was likely a woman known by Tallmadge or Woodhull in order to have been included in the Culper Spy Ring.
Was she the wife of a friend? Servant? Slave? Maybe she was not connected to Tallmadge and Woodhull at all but was brought into the ring by another agent. Morton Pennypacker, an early Culper Ring historian, first suggested in 1948 that she was the secret wife of Robert Townsend, an agent (designated by 723) living in New York City during the British occupation. This is the theory historian Corey Ford finds most compelling in his 1965 A Peculiar Service, which takes an in depth look at 1770s New York. This romantic possibility has been taken up by historical novelists, and it appeals to readers who love a tragic romance. But is it true?"
"Agent 355 may only be a figment of overactive imaginations, and many historians remain unconvinced of her existence beyond being just what Woodhull said, ‘a lady of my acquaintance.’ Female spies were uncommon but not nonexistent in the American Revolution. Some operated on their own, sending information to husbands or brothers in the army, and others were part of more organized networks. In many situations, women found themselves the holders of important information simply because men assumed they were not listening or could not understand the significance of what they were overhearing or observing."