4 Infamous Intelligence Failures

The War Years (1775-1783)

March 24, 2015
by Michael Schellhammer Also by this Author


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Battles are complicated events where conflicting or unclear information can confuse even good generals.  Here are some examples of when American intelligence systems failed, usually with terribly tragic results.


In late 1775 the Continental Congress planned to neutralize threats from Canada by seizing Montreal. Gen. George Washington, commanding the Continental Army at Boston, decided to support the effort by sending a force north from Boston through the Maine wilderness to seize Quebec. It seemed like a good idea at the time.  Washington expected light resistance at Quebec and an easy passage through the highlands of Maine by way of the Kennebec and Dead Rivers. “I made all possible inquiry as to the distance, the safety of the route and the danger of the season,” he wrote, “but found nothing in either to deter me from proceeding.”[1] He chose the rising star Col. Benedict Arnold to command the expedition.

Washington was way off. He gained much of his knowledge about the northern frontier from a 1761 map by a British Army engineer and underestimated the ruggedness of the terrain.[2]  Arnold’s expedition departed in September and endured an exceptionally harsh passage through the Maine highlands that destroyed their supplies, bled off their numbers, and exhausted the soldiers. Arnold wrote to Washington during the trek, “I have been much deceived in every account of our route, which is longer and has been attended with a thousand difficulties I never apprehended.”[3] Slowed by the difficult northward trudge, the expedition did not arrive outside Quebec until December 13. Then they faced British reinforcements that arrived only days before them.  Arnold wrote Washington, “had I been ten days sooner Quebec must inevitably have fallen into our hands, as there was not a man there to oppose us.”[4] Their second adversary, the brutal Canadian winter, also arrived.

A week later the other half of the American invasion force, Brig. Gen. Richard Montgomery’s troops from Montreal, joined Arnold. The combined force attacked Quebec in a snowstorm in the early morning hours of December 31. The assault failed at the cost of 200 American lives. Montgomery was among the dead and Arnold severely wounded.

Had the Americans applied their intelligence more effectively, they could have avoided, or at least better handled, this dramatic but disaster-prone expedition.


In August 1776, 15,000 British troops under Gen. William Howe landed on Long Island, threatening New York City. In between them and Manhattan stood a fortified American defensive line south of Brooklyn.

Incorporating a rugged ridge known as the Gowanus Heights, the American line was a solid defense. But at that early stage of the war the Continentals lacked both a spy network on Long Island and an effective cavalry force. The result was that neither Gen. Washington nor Maj. Gen. Israel Putnam, the commander of the defenses, fully understood the battlefield or British intentions and movements. The Americans heavily defended and fortified three natural passes that formed avenues through the Heights; the Martense Lane Pass, Flatbush Pass, and Bedford Pass. But the Jamaica Pass, at the east end of the line, went unfortified. Only two battalions of riflemen under Col. Samuel Miles had orders to watch the area and report any enemy movement.  The commander of the left of the American line, Maj. Gen. John Sullivan, also posted a patrol of five mounted officers to observe the Jamaica Road which ran through the pass. Sullivan later wrote that he was “very uneasy” about the road, “through which I had often foretold the enemy would come, but could not persuade others to be of my opinion.”[5]

Sullivan’s concern was valid. Howe’s British troops thoroughly scouted the area and gained information from local Loyalists. His subordinate, Gen. Henry Clinton, also knew the area from time he spent there in his youth. “I took some pains to reconnoiter” Clinton wrote, which led him to realize that the Jamaica Pass offered an avenue to maneuver behind the Continental defenses.[6] Clinton suggested to Howe a British attack through the pass to turn the American flank.

Howe detested Clinton, but grudgingly agreed with the plan. On the night of August 26, Clinton marched east to Jamaica Pass with about 10,000 troops, two-thirds of the British force.  They moved, unnoticed, within two miles of a brigade of New York militia under Brig. Gen. Nathaniel Woodhull. At Jamaica Pass, Gen. Sullivan and Col. Miles perceived signs of the enemy advance but whether they properly warned their senior commanders is unclear.[7] That night Clinton’s troops captured Sullivan’s mounted patrol and learned that Jamaica Pass was essentially unguarded.

The next morning, British and Hessian troops pinned down the Americans at the Martense Lane and Flatbush Passes. At about the same time Clinton and Howe personally led their main force through Jamaica Pass to overwhelm the American left flank. Putnam’s defensive line crumbled and the troops retreated to Brooklyn.

Washington took personal command of the Long Island defenses but with his forces outnumbered and outflanked the situation was hopeless. On August 29 Washington evacuated his forces to Manhattan, which relinquished Long Island to the Crown for the rest of the war.


In July 1777, Gen. Howe’s army departed New Jersey by sea in a naval convoy of over 200 ships. Washington had little intelligence on its destination, and for weeks he thought that Howe was headed for the Hudson River, Philadelphia, or South Carolina. Howe’s landing at the north end of the Chesapeake Bay at the end of August pointed to Philadelphia as Howe’s target.

Washington chose to defend Philadelphia on the banks of Brandywine Creek, southwest of the city. The American defense adequately covered five fords across the creek, and Washington was wary of an enemy crossing on his open right flank. There, he posted Maj. Gen. John Sullivan and cavalry under Col. Theodorick Bland to cover three more fords and the vulnerable flank. But the American reconnaissance was, again, incomplete.  Two miles to the west, beyond where Sullivan and Bland watched, two more fords crossed the Brandywine.  Just as at Long Island, Howe found the fords thanks to thorough scouting and a local Loyalist.  Much like Jamaica Pass, Howe knew that the open crossing offered an avenue to turn the American right flank.

The battle of Brandywine nearly repeated the battle of Brooklyn.  On September 11 Howe launched a diversionary attack on the American front.  At the same time Howe and Gen. Charles Cornwallis led a larger force to the northwest, crossed the Brandywine at the unguarded fords, and crashed onto the American right flank. Washington received so many confusing reports of the action that he later told Congress, “the intelligence received of the enemy’s advancing up the Brandywine, and crossing at a ford about six miles above us, was uncertain and contradictory.”[8] The Americans repositioned their line and fought stubbornly, but could not halt the British attack.

Washington withdrew his army east to the town of Chester and two weeks later Howe’s army marched into Philadelphia.


Gen. Horatio Gates, the famed victor of Saratoga, took command of the Continental Army’s Southern Department at a camp at Hollinsworth’s Farm on the Deep River in North Carolina on July 25, 1780, already armed with intelligence. The bulk of the British and Loyalist army under Lord Charles Cornwallis was at Charleston, South Carolina. According to Gen. Thomas Sumter of the South Carolina militia, Lord Francis Rawdon held an exposed post at the town of Camden, South Carolina with only 700 Loyalist troops. Gates decided to march to Camden and sweep away Rawdon’s outpost, and his army departed on July 27.

Gates was making a series of intelligence mistakes. To begin with, he failed to understand his area of operation. His senior commanders suggested somewhat circuitous routes to Camden where the army could sustain itself, but Gates chose a route that was direct but heavy in Loyalist sentiment and barren of forage. This forced the Americans to consume meager rations of green corn, peaches and thin soup that some officers thickened with wig powder. Gate’s second error was that he moved with a cavalry force that was too small to adequately scout ahead and keep track of enemy dispositions. “Fatal mistake!” observed the veteran cavalryman Lt. Col. Henry Lee.[9] The Americans closed on Camden on August 15 unaware that Cornwallis’s army was not in Charleston, but actually concentrated at Camden.

It was on August 9 that Cornwallis, who “was regularly acquainted by Lord Rawdon with every material incident or movement” the Americans made, as he later wrote, learned that Gates was headed toward Camden.[10] Marching from Charleston, Cornwallis’s army arrived at Camden two days before Gates. Continental and Loyalist cavalry patrols clashed the night of August 15, revealing the presence of Cornwallis’s force. Gates’s adjutant, Col. Otho Holland Williams, recalled that when Gates learned that he faced Cornwallis’s entire army, “the general’s astonishment could not be concealed.” Gates called a council of war and asked his senior commanders, “Gentlemen, what is best to be done?”[11]

The Council agreed that they had no choice but to fight Cornwallis the next day, and with that, Gates’s subordinate commanders began sharing the intelligence mistakes. With roughly 3,000 soldiers the Americans outnumbered the British by about 800 men. Gates formed his line of battle in the early morning of August 16, but made the mistake of posting his most inexperienced soldiers, the North Carolina and Virginia militia, on the left of his line where they would oppose the most senior and experienced British brigade. As a former king’s officer Gates should have known that by tradition, British commanders routinely assigned their most senior units to the right side of their battle lines. He also should have realized the advantage that gave the British against the militia he expected to fight them. The reasons for Gates’s decision, and the extent that the subordinate American commanders accepted or disagreed with the assignment, is open to debate. Either way, the decision rebalanced the odds in Cornwallis’s favor.

Gates opened the battle by advancing the militia on the left of his line but Cornwallis immediately counterattacked against the move. The advance of the veteran British regulars set the American militia to flight. The American line crumbled and the cavalry of Lt. Col. Banastre Tarleton’s British Legion swept in and completed the rout. American losses were probably 250 killed and 800 wounded, many of whom were captured, compared to 68 killed and 256 wounded in Cornwallis’s army. The loss at Camden was an absolute disaster and a major blow to American cause in the South.[12]

This is only a partial list of how commanders employed and interpreted their intelligence.  Please feel free to share other examples with your comments.

[1] Washington to the President of Congress, September 21, 1775, Writings of George Washington, Vol. 3, accessed January 5, 2015, http://etext.virginia.edu/washington/fitzpatrick/.

[2] Robert McConnell Hatch, Thrust for Canada: The American Attempt on Quebec in 1775-1776 (Boston; Houghton Mifflin, 1979), 62.

[3] Arnold to Washington, October 27 1775, George Washington Papers at the Library of Congress, accessed January 5, 2015, http://memory.loc.gov/cgi-bin/ampage?collId=mgw4&fileName=gwpage034.db&recNum=605.

[4] Arnold to Washington, November 20 1775, George Washington Papers at the Library of Congress, accessed January 5 2015, http://memory.loc.gov/cgi-bin/ampage?collId=mgw4&fileName=gwpage034.db&recNum=890.

[5] Sullivan, letter dated October 25, 1777, in The Bulletin of the Historical Society of Pennsylvania, Vol. I, 1845-1847 (Philadelphia, Merrihew & Thompson, 1848), “Papers Relating to the Battle of Brandywine,” 52.  Sullivan’s letter could have been self-serving – he wrote it a year after the battle as part of his defense of his actions at the battle of Brandywine.

[6] Sir Henry Clinton, The American Rebellion: Sir Henry Clinton’s Narrative of His Campaigns, 1775 – 1782, with an Appendix of Original Documents, William B. Willcox, ed., (New Haven: Yale University Press, 1954), 41.

[7] See Barnet Schecter, The Battle for New York: The City at the Heart of the American Revolution (New York: Walker & Company, 2002), 133-135.

[8] Washington to The President of Congress, at Midnight, Chester, September 11, 1777, Writings of George Washington, Vol. 9, accessed February 11, 2015, http://etext.virginia.edu/washington/fitzpatrick/. Adjutant General Pickering actually wrote this dispatch at Washington’s direction.

[9] Henry Lee, The Revolutionary Memoirs of General Henry Lee, Edited with a Biography of the Author by Robert E. Lee (1812, reprint, New York: DeCapo Press, 1998), 172.  Lee was not assigned to the Southern Department in August 1780, but I consider his professional observation valid.

[10] Charles, Earl Cornwallis to Lord George Germain, August 21 1780, State Records of North Carolina XV: 269-273, accessed February 11, 2015, http://www.battleofcamden.org/cornwallis2germain_txt.htm.

[11] Otho Holland Williams, A Narrative of the Campaign of 1780, (A. E. Miller, Charleston, South Carolina, 1822), accessed February 15, 2015, “Documentary History of the Battle of Camden, 16 August 1780,” http://battleofcamden.org/.

[12] For a thorough assessment of how Gates and the entire Southern Department performed at this battle, see “Unlucky or Inept?  Gates at Camden,” by Wayne Lynch, https://allthingsliberty.com/2014/05/unlucky-or-inept-gates-at-camden/.


  • Great article; Brooklyn was certainly a great intelligence blunder. I wonder if Washington had better information about the flanking maneuvers to his left flank if he would have pulled back Stirling’s forces or reinforced his left?

    Paoli was also a huge intelligence blunder. Then again, the whole Philadelphia campaign was a disaster in intel. Anyway, I enjoyed the morning read!

    1. Thanks Thomas! Your question about what might have happened at Brooklyn is fascinating to ponder. Israel Putnam had the direct command of the American lines at Brooklyn and I think that Old Put was not one to withdraw his line unless pressed.

      Paoli is a great choice for a failure. Gen. Wayne took a purposefully close to Howe’s army, but under the false impression that the British were unaware of his presence. It appears that he may have received information on the night of Sep. 20-21 that the British knew where he was and intended to attack. Wayne increased his pickets for advance warning of an enemy advance but that was not enough to hold off the bayonet attack of three regiments under Maj. Gen. Charles “No Flint” Grey. It appears that Wayne put up a good fighting retreat, but there is no doubt that a lack of understanding about British capabilities and intent led to his disposition. He paid for his mistake with about 200 dead and 100 wounded, and a defeat that is forever linked to his name.

  • Good article Mike. All your examples feature the lack of “situational awareness” or simply a sound knowledge of the geography on which you are fighting. Washington, and especially Greene in the southern campaign, did much better when their scouting and terrain knowledge were more capable. I look forward to future articles where you discuss some strategic as well as tactical intelligence failures and successes.

    1. Thanks Ken! Your observation is right on. In this piece I’ve applied some modern terms to the Revolutionary War and “situational awareness” probably fits into that category as well, though accurately. Another way to look at it is that in these examples, American commanders failed to keep track of enemy dispositions and movements, which is a significant tactical intelligence failure on its own.

      Another aspect to consider is that the examples also address times when American commanders were guilty of expecting their adversaries to react and maneuver in the way that Americans expected them to, which is another type of intelligence failure.

      As you mention, there were certainly times when Washington’s reconnaissance and situational awareness, Greene’s too, was much better.

  • An interesting list, Mike. The “Quebec” intelligence failure is different than the other three in that it was more of a poor strategic assessment than a failure to understand what the enemy was doing at the tactical level. The most spectacular failure in “strategic” intelligence has to be the assessment by Congress and General Washington that no major British offensive would be launched from Canada in 1777. As a result, Burgoyne achieved almost perfect strategic surprise at Ticonderoga/Mount Independence, forcing their prompt abandonment on July 6, 1777. Fortunately, Burgoyne failed to capitalize on the situation fully by capturing the bulk of the Army of the Northern Department before they could retreat, although he came within a whisker of doing so.

    Regarding the problem of achieving “situational” awareness, I am inclined to be somewhat forgiving of commanders back in those days, when “real time” information simply wasn’t available and even with heavy scouting, anticipating the movements of the enemy was largely guesswork. Armies were still blundering into each other as late as the Civil War and beyond.

    1. It might interest Ron et al (whoever Al is) to know that I have an article in the queue that, in part, addresses the American intelligence situation at the start of the Burgoyne campaign. Without offering a spoiler to my article, I can say that the bottom line for the Americans is that, even if they had known of Burgoyne’s intentions before he began his move up Lake Champlain, they probably could not have done anything that would have stopped him at Mount Independence and Ticonderoga. They simply did not have the necessary numbers of men to hold that complex and present some sort of resistance in the New York city area. Destiny had declared that the American hold on one end or the other of the Hudson would collapse.

      1. Mike: Wow, I’m thrilled to hear you are going to do an article on this! I agree completely with you, but with this difference–if the Americans had assessed British intentions with reasonable accuracy, they would almost certainly not have put the bulk of the Army of the Northern Department at risk of capture by leaving them at Ticonderoga/Mount Independence with low levels of supplies and equipment and miles more fortifications than they could occupy. Had that army been lost, there were no more than 3 Continental regiments available (at Peekskill, as I recall) to resist Burgoyne. He would have gotten to Albany easily, although I’m not sure what he would have done after that. With Schuyler in charge, assuming he knew what was coming, based upon my review of his detailed correspondence I am pretty certain he would have seriously considered putting a smaller, adequately supplied and equipped force on Mount Independence to delay Burgoyne until the swarms of militia could be concentrated with the core Continental Regiments to mount a defense. Query whether the logistical issues could have been surmounted though.

  • Thanks Ron! I don’t disagree with your idea that the overall problem with Arnold’s Quebec expedition was a flawed strategic assessment. Part of that assessment involved intelligence-related information, other parts were politically-oriented. It is good to note that the original American assessment was that the Canadians were not likely to offer significant resistance at Quebec and they were initially correct – Quebec’s civilian leaders were not 100% set on fighting the Americans before a stalwart British commander arrived on the scene. Either way, the situation changed by the time the Americans made their assault, and the Americans failed to adapt to the changes. I am not sure that in their assault on Quebec, Gen. Montgomery and Arnold fully understood the British capability and dedication to holding the city.

    It was a less precise and real-time environment, to be sure. However, I would not consider intelligence in the Revolutionary War to be guess work. Good commanders understood how to employ their intelligence systems, from scouts, cavalry, guides, and spies, in a coordinated effort to gather accurate information. It often worked very well in some of famous actions.

    Thanks for reading and commenting!

    1. As you point out the decision to invade Quebec was flawed due to lack of intel on British troop strength and receptivity of the Canadian populous. But even if the Americans had seized Quebec in 1775, they probably would have promptly lost it when confronted by the combined land/sea reinforcements which arrived in 1776. Other than Boston with its natural defenses and hostile population, the Americans were not able to hold a major port city throughout the war.

      1. Gene – I agree. I suppose one could say that the Canada invasion was also a strategic intelligence failure, in that the Congress underestimated Britain’s resolve and capabilities to maintain the province.

        I often wonder how the American soldiers and resources that went to waste in the Canada assault, especially a good leader like Montgomery, could have been better applied in later campaigns.

        And since this is where Arnold received his first wound, I wonder if this failed campaign began sowing the seeds of disgruntlement in Arnold’s flawed mentality.

    2. Mike: Perhaps “guesswork” is a little too strong of a word, and I do not mean to suggest that enormous effort wasn’t made to gather intelligence during the Revolution, but it has been an illuminating experience for me reading correspondence from generals of this period agonizing over how to respond to dribs and drabs of inconsistent and confusing information from multiple sources of dubious reliability, in order to make decisions upon which the fate of an army or perhaps a war might depend. Yes, it’s a problem with which military leaders of all eras have to contend, but I believe it was far more difficult to do prior to, say, World War I. So, if a general failed to detect a particular action by the enemy, it is not necessarily due to a lack of effort, or even the result of a poor effort; sometimes “stuff happens”.

      Regarding Quebec, my recollection from looking at some of Montgomery’s correspondence immediately prior to the invasion was that he had a quite accurate assessment of the strength of Carleton’s forces in Canada, down to the specific units, e.g., “MacLean’s rabble”. The primary problems, as noted in comments below, were logistical (and the small pox).

      1. No arguments there Ron. Being used to reading history in books with maps can sometimes drive one to wonder how a commander missed what seem like clear signs. In reality, figuring out the enemy activity was an extremely difficult and confusing task for any commander – it was tough before campaigns started, and even tougher in combat. Commanders didn’t have the nice overhead views we’re all used to seeing in books.

        Brandywine is a good case in point. Imagine for a moment Washington and his staff at his headquarters, amid the noise of battle, receiving fragmentary reports. It could not have been easy to sift and understand the reports and then assemble them in into a coherent picture. There is an old soldier’s maxim, “the first report from combat is always wrong.” How could Washington know which reports were accurate and which were not? How could he put one report together with another to create a cohesive picture? The enemy does not pause to let commanders figure things out. No doubt about it, figuring out combat intelligence was a tough job.

  • I think it’s worth noting that all four of these examples are about the American side. Are there equivalents for the British commanders, aside from the Burgoyne campaign plan mentioned above?

    1. Right on J.L. I wrote these two pieces from the American perspective for consistency, but there could certainly be a corresponding list for the British. Applying the same criteria, some British intelligence failures could be:

      1. Lexington and Concord – Gage’s counterintelligence efforts to keep his plans secret failed.
      2. Breed’s Hill – As I think you’ve noted on your blog, British plans to occupy the Charlestown Heights leaked to the Americans and may have contributed to the Rebel fortification of Breed’s Hill. Then Howe misread, or failed to fully appreciate, the terrain on the Charlestown Heights and Rebel capabilities to hold their position.
      3. New Jersey – Howe misread American capabilities to harass and attack his dispersed garrisons.

      There are others, and of course there could be a list of British intelligence successes. But that’s a different article.

      Thanks for commenting!

  • Regarding Quebec, I would qualify any reported “intelligence failure” committed by Washington as something that the Continental Congress aided and abetted. Before any invasion even started, the congress knew it had a huge challenge on its hands as evidenced by its sending an eighteen-page missive to the Canadians seeking their involvement in the rebellion, whereas they sent a mere two sentences to the thirteen colonies. They knew how entrenched the Canadians were in their culture and it was going to be difficult to have them agree to abandon their British overseers.

    Military considerations aside, the Congress further failed to follow up after Montgomery’s early successes in providing needed specie that the Canadians required. Despite pleading from Schuyler and Montgomery for assistance, they further compounded their difficulties in failing to send experienced politicians directly into the theater of operations to assist sympathetic Canadians in forming appropriate democratic measures to overcome any reluctance of those withholding support for the rebel cause.

    This was more than just a military failure, but one that might have succeeded had the Congress acted aggressively in support of Washington.

  • Mike, good follow-up article. In response to Mr. Bell’s point, I would judge the worst British mistake was their handling of Arnold’s “write-in” defection negotiations. Others might argue it was Gage’s decision not to use Dr. Church’s inside information to seize and arrest the Sons of Liberty leadership. However, with a source like Church, any aggressive action is a double-sword.

  • Just got around to reading this great article. A good commander can never have too much intelligence though sifting through disparate and contradictory bits was probably maddening. In Brooklyn, it’s difficult to understand why Putnam wasn’t more aggressive about his scouting as there were opportunities to observe the British deployment. Surely, his experience in northern New York during the French and Indian War would have taught him the value of advance scouting. As to the American defensive strategy, if you’re going to watch and fortify three passes, why not four? The Americans had built Fort Putnam on their far left so it wasn’t as if there was no thought that the British could put pressure on the left, even if it were to turn out that it was just a feint. Once the British began to move, a reconnaissance-in-force through the Jamaica Pass probably would have been the sensible move. I think the intelligence failure of the Americans, in the case of Brooklyn, was mostly due to inexperience, a more complicated battlefield covering a large area and the lack of imagination on the part of the commanders.

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