Intelligence in the Battle of Princeton Two missions of military intelligence collection , both of which came to a climax on 30 December 1776 , contributed to the Continental Army ' s victory in the Battle of Princeton . Joseph Reed and the Philadelphia Light Horse . The " obscure and doubtful " intelligence on which General Washington had to base his next action frustrated him after a decisive victory in the Battle of Trenton . Washington observed to Adjutant - General Joseph Reed that the strength of the British in the area had greatly discouraged spies for the revolution ; Reed had the same opinion , having himself encountered the " poor " and " terrified " inhabitants of Bordentown only days before . Red rags hung from almost every house door in expression of Tory sympathies ; homeowners were hastily tearing them down in accordance with the clear turn of events . Reed considered the residents " effectually broken and hardly resembling what they had been a few months before . " Reed was a New Jersey native , and proposed to Washington that he lead a group of cavalrymen from the Philadelphia Light Horse toward Princeton to enlist spies . The Philadelphia Light Horse was a group of twenty - one wealthy young men that volunteered its service to General Washington . They paid their own expenses , and , unlike most Continental troops , were gentlemen . The Light Horse wore chocolate brown uniforms , high - topped riding boots , and black hats with silver cords and bucktails . David Hackett - Fischer speculates that ragged Continental infantrymen jeered them as they approached Trenton on matched chestnut horses . Washington approved the mission , and sent Reed with seven cavalrymen . The residents on the road to Princeton , however , were afraid . In Reed ' s words , the " arms and ravages of the enemy " had terrified the population ; though they were " otherwise well disposed , " no reward could tempt them to go into Princeton on a mission of espionage . Stories of captured revolutionaries who were starving in the prison hulls of New York , along with more immediate accounts of British plunder and rape in New Jersey , were doubtlessly a strong deterrent to participation in the cause of the Continental Army . Reed and his men were determined to return with valuable information . Expecting that the rear of Princeton would be poorly guarded , they circled the town . They were about a half - mile southeast of Clarksville , almost in view of Princeton itself , when they spotted a British soldier walking between a barn and a house . Reed assumed he was looting , and sent two cavalrymen to take him prisoner . The Light Horsemen kept the barn between themselves and the house to approach closely without being noticed . A second and third soldier appeared as they rode , and Reed ordered the rest of his men to charge . As things worked out , Reed ' s men were outnumbered , but they were also in the right place at the right time . Most of the twelve British soldiers were busy " conquering a parcel of mince pies " as the Light Horse surrounded the house . Seven cavalrymen , six of whom had " never before seen an enemy , " thus forced the surrender of twelve well - armed British dragoons . Reed and the Light Horse returned to Trenton with their captives mounted behind , probably to a much different reception by Continental infantrymen . The prisoners were separately interrogated , and revealed that General Grant had reinforced British troops at Princeton , that the force assembled there comprised over 8 , 000 trained soldiers , and that the British intended to advance on Trenton . This was critical intelligence ; at the time , Washington commanded only 4 , 700 men , many of whom were new recruits , and all of whom were poorly equipped . " A Very Intelligent Young Gentleman " . On 12 December , Washington had written a letter to Colonel John Cadwalader , the senior officer of a militia called the Philadelphia Associators . This letter emphasized what Washington understood as an imminent necessity for both intelligence and counterintelligence . Spare no pains or expense to get intelligence of the enemy ’ s motions and intentions . Any promises made , or sums advanced , shall be fully complied with and discharged . . . Every piece of intelligence you obtain worthy of notice , send it forward by express . . . Keep a good lookout for spies , and magnify your numbers as much as possible . Three days after receiving these orders , Cadwalader replied that he had sent " several persons over for intelligence . " Two weeks later , on the morning of 31 December , he identified one of his spies , " a very intelligent young gentleman " who had just returned from Princeton with details on the British force and its disposition . . . . there were about five thousand men , consisting of Hessians and British troops — about the same number of each . . . He conversed with some of the officers , and lodged last night with them . . . No sentries on the back or east end of the town . They parade every morning an hour before day , and some nights lie on their arms . An attack has been expected for several nights past — the men are much fatigued , and until last night [ were ] in want of provisions , when a very considerable number of wagons arrived with provisions from Brunswick . . . In accordance with Washington ’ s orders , the spy magnified the Continental Army ’ s numbers , telling them the best accounts reported 16 , 000 troops . This surprised the British , who had expected no more than five or six thousand . The same young gentleman , by coincidence , was " near the party of chasseurs " when they were captured by Reed and the Light Horse , and was with the British officers when they received news of the attack . Cadwalader included with his letter a " rough draft of the road from this place , " meaning from Crosswicks , where Cadwalader was at the time , to Princeton . The map was highly detailed . Cadwalader put numbers next to bridges , for example , to indicate the number of soldiers defending them . A block of text perpendicular to the others ran up and down the right side of the map , highlighting a road : " This road leads to the back part of Princeton which may be entered anywhere on this side — the country cleared , chiefly , for about 2 miles . . . few fences . " The map was particularly helpful in that it displayed not what existed at the time Cadwalader drew it up , but what would exist by the time General Washington could act on the intelligence it provided . In other words , the map was estimative , indicating " works begun , and those intended this morning . " Before he heard from Cadwalader , Washington had only three pieces of intelligence , all of which were ascertained through prisoner interrogation : firstly , that General James Grant had reinforced British troops at Princeton ; secondly , that the aggregate force there comprised over 8 , 000 soldiers ; and thirdly , that they intended to advance on Trenton . It is likely that Cadwalader ' s report , obtained from a plainclothes spy who ingratiated himself with British officers , relieved Washington both by suggesting a substantially weaker enemy force of around 5 , 000 men and by providing detailed , actionable information on their positions and disposition . Washington immediately sent a large Continental force up the Post Road with orders to delay any British movement toward Trenton . It advanced under the cover of darkness on New Year ’ s Eve , occupying a position six miles from Nassau Hall . The British spotted them at dawn and sent its First Battalion light infantry , along with two Hessian companies to engage the revolutionaries . The British cleared the road , but at a heavy cost . St . Clair ' s Proposal . On 2 January 1777 , British troops advanced in force ; the Continental Army held its ground at Assunpink Creek in the Second Battle of Trenton . That evening , Washington convened a council of war . His senior officers , including Reed and Cadwalader , were there , along with local citizens whom Washington invited both to attend the meeting and to speak freely . Washington ' s officers considered several alternatives , none of which seemed advantageous . General Arthur St . Clair proposed a surprise attack on the enemy ’ s rear ; if Continental troops could reach Quaker Bridge unobserved and unopposed , he argued , they would only have to proceed north about six miles before reaching Princeton . Reed confirmed this estimate , and contributed his own knowledge of the terrain . When he led the Light Horse to Princeton , he mentioned , they saw no British on the back roads . One officer later recalled that " two men from the country , near the route proposed , " were " called to the council for their opinions of its practicability . " St . Clair ' s idea was bold . Washington might have rejected it outright had it not been for the additional intelligence he was able to solicit from ordinary colonists on the evening of 2 January . Aftermath . When Washington wrote John Hancock three days later , on 5 January 1777 , it was with good news . I have the honor to inform you , that , since the date of my last from Trenton , I have removed with the army under my command to this place [ Pluckemin , New Jersey ] . . . Their large pickets advanced towards Trenton , their great preparations , and some intelligence I had received , added to their knowledge , that the 1st of January brought on a dissolution of the best part of our army , gave me the strongest reasons to conclude , that an attack upon us was meditating . Washington described the Continental Army ' s march to Princeton , " by a roundabout road , " as its baggage was quietly moved to Burlington . The Battle of Princeton was a decisive victory for Continental troops , which took the British force by surprise . This was just the pick - up colonists needed ; The Pennsylvania Journal wrote that if Washington had lived in the days of idolatry , he would have been worshiped as a god . Washington formally discharged the Philadelphia Light Horse three weeks later , saying that " though composed of gentlemen of fortune , " they had " shown a noble example of discipline and subordination , " and in several actions had " shown a spirit and bravery which will ever do honor to them , and will ever be gratefully remembered by me . " In September 1779 , the Light Horse reconvened at Washington ’ s own request , and served the Continental Army until the British surrender at Yorktown two years later , in October 1781 . The Philadelphia Light Horse enjoyed an honorable legacy after the American Revolution . In his 1816 memoir , General Wilkinson praised the cavalrymen for their 30 December expedition . This " little act of decisive gallantry " had " tended to increase the confidence of the troops , and certainly reflected high honor on the small detachment . " Eight years later , at a reception held for General Lafayette , John Lardner and William Leiper — the sons of two Light Horse cavalrymen who were part of the reconnaissance mission — wore the breastplates of British officers captured that day . Published in 1875 , the Light Horse ’ s narrative of the 30 December expedition cooperates almost perfectly with that of Joseph Reed . The sole discrepancy is the number of men that Reed took with him . The Light Horse maintains that Reed took twelve , not seven , cavalrymen with him on the mission to Princeton , while Reed clearly asserts in his handwritten account that he proceeded on that day " with seven gentlemen , " five of whom he names : Messrs . Caldwell , Dunlap , Hunter , Pollard , and Peters . Assuming that the two others are Messrs . Lardner and Leiper , five men of the Light Horse ’ s narrative remain unaccounted for . Whether Reed excluded , by accident or by design , the names of men that accompanied him on such a vital mission , or whether members of the Light Horse sought credit , " ex post facto " , for a mission with which they were not involved , is unclear . History seems to have sided with the Light Horse ; most accounts of the expedition mention twelve , not seven cavalrymen . A notable exception is David Hackett Fischer ’ s " Washington ' s Crossing " , which — perhaps nodding to the discrepancy — avoids the mention of a figure . The legacy of the Philadelphia Light Horse stands in stark contrast to that of Cadwalader ' s anonymous and " intelligent young gentleman . " He might have been a student at Princeton , which had been closed since the British invasion . It is likely that he had no surviving family ; none claimed his story after the war or since .