October 29, and Tallmadge replaced him as intelligence chief. Early operations Woodhull traveled to New York City every few weeks to gather intelligence. His married sister, Mary Underhill, lived there and gave him a valid reason to visit. He was questioned at a British checkpoint on October 31, 1778, which increased his anxiety about the dangerous mission, but he returned to Setauket with valuable information about the British supply fleet. He provided a precise report on November 23 with the identity of British units and the numbers of troops and dispositions in New York City, which proved his worth as a spy. Woodhull soon recruited his brother-in-law, Amos Underhill, to gather intelligence; the latter ran a boarding house in the city with his wife, Mary, but Underhill's reports were often too vague to be of much value. At first, Woodhull had to return to Setauket to pass messages to Caleb Brewster, which Brewster would take to Tallmadge or to receive messages from Tallmadge via Brewster. Tallmadge set up couriers in December who would take messages the between New York and Setauket, initially Jonas Hawkins then mainly Austin Roe beginning in the early summer. The courier's task was to get the letters to Brewster, who would pick up messages at one of six secluded coves near Setauket and take them across Long Island Sound with his rotating whaleboat crews to Tallmadge at Fairfield, Connecticut. Tallmadge would then take them to Washington's headquarters. The time-consuming task was replaced in January 1779 by the assignment of express riders to take the messages from Tallmadge to Washington. Local tradition claims that Anna Strong, a resident of Setauket and a friend and neighbor of Abraham Woodhull, helped pass along messages from the spy ring by posting prearranged signals to indicate when one of the spies was ready to submit intelligence. If she hung a black petticoat on her clothesline, it meant that Brewster had arrived in town in his whaleboat. Also, she would hang a quantity of white handkerchiefs to indicate which of the six hiding places he was in. Woodhull used her signals to meet Brewster or to drop messages at one of the meeting places. The historian Richard Welch writes that the tradition of the clothesline signal is unverifiable, but it is known that the British suspected a Setauket woman who fit Anna's profile of Patriot activities. Brewster occasionally would add his own