Tallmadge was a major in the
2nd Continental Light Dragoons and was initially commissioned on June 20, 1776. Tallmadge was in charge of bringing intelligence from British-controlled New York to the Continental army, and he did so by assembling a network of spies known as the
Culper Ring, with the help of
Abraham Woodhull and
Robert Townsend. The Culper Ring was involved in revealing the betrayal of Major General
Benedict Arnold. Arnold's British contact, Major
John André, was caught and taken to North Castle, where the commander, Colonel
John Jameson, ordered Lieutenant
Solomon Allen to take the incriminating documents found with André to Arnold, who was still in command at
West Point. Tallmadge suspected André of being a spy and Arnold of being his accomplice, and tried to have Jameson reverse his orders. He was unsuccessful, but did convince Jameson to send a rider and take André to Salem, eight miles east of the Hudson River, and to send the documents to Washington. Allen still reported to Arnold with Jameson's note outlining the events. Later, Jameson was chastised by Washington for warning Arnold and allowing his escape. André was placed in Tallmadge's custody, awaiting execution. On November 21, 1780, Tallmadge and his dragoons rowed across Long Island Sound from
Fairfield, Connecticut to
Cedar Beach in
Mount Sinai, New York. The next day, they proceeded to the south shore, where they captured and burned down
Manor St. George. On their march back to Mt. Sinai, Tallmadge stopped in
Coram, New York and ordered the burning of 300 tons of hay which the British had been stockpiling for the winter. Washington, on hearing the news, sent the following letter to Tallmadge: I have received with much pleasure the report of your successful enterprise upon Fort St. George, and was pleased with the destruction of the hay at Coram, which must be severely felt by the enemy at this time. I beg you to accept my thanks for your spirited execution of this business. Tallmadge served at Washington's headquarters from March 1781 until the Continental Army was disbanded in November 1783. He was admitted as an original member of The
Society of the Cincinnati in the state of
Connecticut when it was established in July 1783 and
brevetted to the rank of
lieutenant colonel on September 30, 1783. and continues to be represented by a living descendant in the society today. ==Later life==