Abraham Woodhull was born in Setauket in 1750 to parents from two of Long Island's prominent families. His father was a local judge who was linked to Patriot politics. Before 1776, Woodhull may have briefly served with a militia company, but there is little to tie him to either side of the war until his spying. Historian Alexander Rose claimed Woodhull began working as a spy as part of the conditions of his early release from prison in Connecticut for engaging in black market trading.
Regardless of Woodhull's motives, he began spying in November of 1778. Woodhull's plan was to travel to Manhattan pretending to visit his married sister and her family at her boardinghouse. While in Manhattan, he would wander the city to collect information, and then return to Setauket where he could dispatch the information to Tallmadge wirting with the pseudonym "Samuel Culper." Predictably, this initial plan had problems. Woodhull's visits to his sister were too frequent to be understandable, especially given the danger. Additionally, he spent all of the time he was supposed to be visiting with his sister wandering the city without an obvious purpose, suggesting that there was another reason he travelled to New York. The British naturally became suspicious by the Spring of 1779. On June 5, 1779, the Long Island-based Queens' Rangers under the command of Colonel Simcoe were sent to the Woodhull family home to arrest Abraham. Abraham was not at home at the time, and avoided arrest, but the Rangers attacked his father.
Clearly, Woodhull's situation was too precarious to continue using the same plan. To escape the immediate danger of arrest, Woodhull sought help from "a friend" who was powerful enough to personally intervene with the "Gen'l Aid," a phrase that seems to refer to one of Major Andre's many military titles. Woodhull recruited Robert Townsend, who lived at his sister's boardinghouse and was distantly related. Woodhull and Townsend also had some similarities in social status. Why Woodhull chose Townsend is not known, but Townsend sent his first report as "Samuel Culper, Junior" on June 20, 1779. Townsend was a much better choice as a spy since he had an obvious reason to be in New York. His mercantile background gave him a good reason to inquire about British troop movements and shipping. While Townsend's intelligence reports were a much better quality than Woodhull's, Woodhull and Tallmadge knew by August that they needed to do something different if they wanted decent Army Intelligence.
On August 15, 1779, Woodhull wrote to Tallmadge, indicating that he planned to travel to New York shortly, and he had a plan involving the "assistance of a lady of my acquaintance" to "outwit them all." Many historians have interpreted this letter to mean that Woodhull recruited another agent who was a woman. Because people did not believe women in the 18th century were capable of independent activities or political allegiances, women were often capable spies. There is no further evidence to indicate that the Culper Ring had a female agent gathering intelligence for them, although there was a woman in Setauket who helped with the network logistics. Less than two months after Woodhull wrote this letter, the Culpers' reports drastically improved, and they were feeding Tallmadge intelligence that could only come from the upper levels of British Headquarters.
With the new structure of the ring, Woodhull no longer carried messages between New York and Setauket. He would simply retrieve Townsend's intelligence from a pre-arranged place on his property, where it was left by a courier. This courier was usually , although another courier, Jonas Hawkins, also served in this role briefly. Woodhull's job now was to simply collect the message, monitor for a signal from the whale boat ferry-man Caleb Brewster, and deliver the dispatches to Brewster. It is generally thought that Woodhull only needed to watch his neighborAnna Strong's clothesline, where she would arrange her laundry to signal Brewster's presence and location. Woodhull only traveled to Manhattan when he felt there was a problem with Townsend he needed to discuss.
The letters Woodhull wrote as cover letters or supplements to Townsend's dispatches are particularly valuable in some cases, particularly where Townsend's letters no longer survive. It was the urgent cover letters Woodhull wrote on July 20, 1780 (coinciding with the British discovery to the arrival of the French Fleet), that make historians think the Culpers discovered the British plans to attack the vulernable fleet.
When Andre was captured and the Arnold affair was discovered, Woodhull continued to report. Woodhull's dispatches often provided more information about the mindset and concerns of the ring, along with the dangers everyone faced. Also, it was Woodhull's dispatches that informed Tallmadge and historians of the capture of "friends" including "one who hath been ever serviceable to this correspondence" on October 26, 1780, during the period of Arnold's spyhunt. At the time Woodhull wrote that letter, Townsend was hiding at Woodhull's family's home, presumably because it would be easier to escape to Connecticut than in the Townsend family home, which was occupied by the British.
In the aftermath of the Arnold plot, Townsend had an extreme emotional response, documented by Woodhull, and refused to continue spying until the following spring. However, Woodhull continued reporting, even though he had little information of any true value. Woodhull's reports were never of a particularly good quality, and after Andre's death, Townsend's few reports were also lacking.
Following the war, Woodhull married his cousin Mary Smith in 1781, and had three with her. He held a few minor political appointments, including Suffolk County Justice, where he served from 1799-1810. His wife died in 1806, an in 1824, Woodhull married a woman named Lydia Terry. He died in Setauket in 1826.