History in 6 Minutes

In 1777, aiming to isolate New England, the British devised a three-pronged assault to gain control of New York's Hudson River Valley. Lieutenant Colonel Barry St. Leger led one prong from Lake Ontario, intending to proceed east through the Mohawk Valley and converge with the others at Albany. Fort Stanwix, situated strategically at the Oneida Carrying Place, posed a critical obstacle.
American General Philip Schuyler tasked Colonel Peter Gansevoort with retaking and restoring the dilapidated Fort Stanwix. As St. Leger's diverse force—comprising British regulars, Hessian Jägers, Loyalists, Canadian militia, and a sizable Iroquois contingent—advanced in the summer of 1777, Gansevoort's men hastily worked on repairing the fort.
Upon arriving at Fort Stanwix on August 3rd, St. Leger demanded surrender, which Gansevoort refused. Subsequently, the British commenced siege operations, though their artillery proved insufficient to breach the fortified walls. They resorted to cutting off supplies and attempting to intimidate the garrison.
Meanwhile, learning of the siege, Brigadier General Nicholas Herkimer assembled approximately 800 militiamen and Oneida warriors to relieve the fort. Informed of Herkimer's approach, St. Leger dispatched a force of Loyalists and Indigenous warriors under Sir John Johnson to intercept them.
On August 6th, Herkimer's column was ambushed in a ravine near Oriskany Creek, triggering the brutal, close-quarters Battle of Oriskany. But it was Willet's stunning raid from Fort Stanwix that ultimately compelled the British allies to abandon the battle in order to protect their camps.
While the Battle of Oriskany devastated the American militia and blew up Herkimer's relief effort, the British and their allies also suffered considerable losses, especially among the Indigenous warriors.
VII. Stalemate and Shifting Morale (August 7-20)
In the days following the twin shocks of Oriskany and Willett's sortie, the siege of Fort Stanwix settled into a tense stalemate. Even so the psychological balance had decisively shifted. St. Leger pressed on with the siege, but his options were limited.74 His artillery continued its ineffective sputtering against the fort's resilient earthen walls.35 So lacking heavy guns, the British resorted to standard siege tactics, beginning the laborious process of digging approach trenches, or "saps," hoping to inch their way closer to the fort's walls, to get close enough to detonate mines underneath the ramparts.19 Progress was agonizingly slow.
Inside the fort, the American garrison held firm. Though they knew Herkimer's relief attempt had failed, but the success of Willett's raid provided a powerful boost to their spirits.19 The captured documents confirmed the enemy's strength but also revealed potential weaknesses. Under Gansevoort's steady command, the defenders remained resolute, conserving dwindling supplies and maintaining vigilance.19
Outside the walls, however, St. Leger's command was steadily disintegrating.43 Morale, particularly among the Indian allies, had plummeted.13 They were deeply angered by their heavy losses at Oriskany, the violation of their camps during Willett's raid, and the lack of promised plunder. Throw in the tedious, unfamiliar nature of siege warfare and Indian discontent was growing quickly.20 St. Leger's attempts to placate them proved ineffective.31 Warriors began to drift away from the siege lines. Discipline frayed, and there were even reports of Indian warriors breaking into British supply stores.31 Compounding St. Leger's problems, his own Loyalist officers, including Sir John Johnson, urged him to abandon the frustrating siege after Oriskany and instead push rapidly down the Mohawk Valley, arguing the militia was broken and could not resist.45 St. Leger, perhaps overly cautious or fixated on the symbolic prize of the fort, disregarded this advice and chose to continue the siege.45
While the Americans were determined, they also recognized their precarious situation. Supplies were finite. They knew another relief attempt was essential to survive. So on the night of August 10th, under the cover of a fierce rainstorm and its accompanying darkness, Lieutenant Colonel Willett once again embarked on another daring mission.26 Accompanied only by Lieutenant George Stockwell, Willett slipped out of a sally port, crawled through the marshy ground surrounding the fort, and successfully evaded enemy patrols.30 Their perilous journey took them fifty miles east through wilderness, swamps, and enemy territory, eventually bringing them to Fort Dayton.30 Their goal was simple. Reach General Schuyler in Albany and plead for a second, stronger relief force.
Willett's desperate plea for help reached sympathetic ears. General Schuyler, despite facing pressure from Burgoyne's main advance further east, understood the critical importance of holding Fort Stanwix.65 He turned to one of his most capable commanders: Major General Benedict Arnold.8 Benedict Arnold, whose reputation for aggressive battlefield command was already well-established made him one of the more controversial commanders on the American side. Arnold who had recently arrived from Washington's main army in an effort to bolster the northern defenses, readily volunteered to lead the relief expedition.44
Around August 20th, Arnold arrived at Fort Dayton(, roughly thirty miles east of Stanwix), having force-marched his troops westward.20 Arnold's force consisted of approximately 700 to 800 Continental regulars.9 Here he met up with Willett and attempted to augment his numbers by recruiting local Tryon County militiamen, but found few takers; the survivors of Oriskany were demoralized and unwilling to face another potential slaughter. Only about 100 militia joined his ranks.9
News that St. Leger's men were digging trenches ever closer to the fort's vulnerable powder magazine added urgency to find an alternative solution.74 Arnold, ever resourceful and quite bold, opted for not for a surprise attack like Herkimer but something far more audacious.9
His plan centered on a peculiar local figure named Hon Yost Schuyler (Hun YOH-st SKY-ler) .20 He was the son of Peter D. Schuyler and Elisabeth Barbara Herkimer. His mother was the sister of American General Nicholas Herkimer. He was also a cousin of American General Philip Schuyler. Despite his patriot family ties, Hon Yost associated more with the Mohawks (who sided with the British) and had Loyalist sympathies. Described variously as mentally impaired, eccentric, or even a "half-idiot," Hon Yost had grown up among the Mohawk people and held a strange influence over them.30 They reportedly viewed his odd behavior and pronouncements with a degree of awe, perhaps seeing him as someone touched by the supernatural, a prophet of sorts.75 He had recently had been captured near Fort Dayton and sentenced to death.20 Arnold saw an opportunity. He offered Hon Yost (Hun YOH-st ) his freedom in exchange for undertaking a dangerous mission.77 To ensure compliance, Arnold took Hon Yost's (Hun YOH-st ) brother Nicholas hostage.20
The deception was carefully staged. Hon Yost's coat was riddled with bullet holes to make it appear he had narrowly escaped his captors.77 He was then dispatched to St. Leger's encampment accompanied by several reliable Oneida messengers who could verify his story, .20 Their mission was simple: spread alarming rumors about the size and speed of the approaching American relief force. Hon Yost played his part brilliantly. He arrived in the British and Indigenous camps, wild-eyed and seemingly terrified, raving about the massive army coming to crush them. He spoke of thousands of soldiers led by the fearsome American general Benedict Arnold who was known as the "Dark Eagle" –.20 When asked how many men Arnold commanded, Hon Yost reportedly gestured vaguely towards the leaves on the trees, implying a number too vast to count.77
The effect on the already demoralized besiegers was electric.9 St. Leger himself recorded in his journal on August 21st the alarming news that "Arnold was advancing, by rapid and forced marches, with 3,000 men," a wild exaggeration of Arnold's actual strength.10 While some Iroquois may have initially doubted Hon Yost's tale, the corroborating reports from the Oneida messengers, coupled with Hon Yost's strange charisma and their own deep-seated desire to abandon the failing siege, tipped the scales.77 Panic swept through the Indigenous camps. Within hours, warriors began packing their belongings and deserting en masse.8

With his crucial Indigenous allies melting away Brigadier General St. Leger found his position untenable.9 The exaggerated reports of Arnold's massive army, combined with the mass desertions, left him no choice. On August 22, 1777, after twenty-one days, St. Leger officially lifted the siege of Fort Stanwix.13
But the withdrawal was anything but orderly. It devolved into a hasty, panicked retreat.20 In their rush to escape the phantom army they believed was descending upon them, the British forces abandoned much of their equipment. Tents were left standing; valuable provisions, ammunition, and other stores were left behind for the Americans.20 Most significantly, they abandoned their entire artillery train – the four small cannons and four mortars whose ineffectiveness had plagued the siege from the start.35 Adding insult to injury, reports surfaced that some of the departing Indigenous warriors, angered and disillusioned, turned on their former allies, harassing the retreating column of British regulars and Hessians. Some accounts suggest several Hessian Jägers assigned to the rear guard were killed or attacked by their erstwhile comrades during the chaotic withdrawal.26
News of the enemy's flight quickly reached Benedict Arnold. He pushed his column forward, arriving at Fort Stanwix (or Fort Schuyler, as the Americans called it) on the evening of August 23rd.22 The weary garrison, who had endured three weeks of siege, erupted in cheers at the sight of their rescuers. Arnold dispatched a party of 500 men in pursuit of the fleeing British, but St. Leger's forces had too much of a head start.26 The American advance party reached the shores of Oneida Lake just as the last of St. Leger's boats were pulling away.26 St. Leger and the remnants of his command escaped back through Oswego and eventually returned to Canada, their part in the grand Saratoga campaign ending in utter failure.9

In all, St. Legers expedition was a total failure. The nature of the retreat – the panic, the abandoned equipment, the harassment by former allies – illustrated the complete collapse of St. Leger's expedition. The fort that the British had expected to fall in days had held, and the western pincer of Burgoyne's grand plan had been decisively broken.
St. Leger failed to not only secure the Mohawk Valley, but failed to rally significant Loyalist support, and, most importantly, failed to reach Albany to link up with Burgoyne.6 Though St. Leger eventually made his way back to Fort Ticonderoga with remnants of his force, he arrived far too late to influence the main campaign.9