Battle of Fort Oswego

Despite facing considerable military weakness, New France managed to secure several early triumphs during the Seven Years' War's North American campaigns, and the engagement at Fort Oswego stands among them. General Montcalm led a combined force of regular troops and Canadian militia against the British stronghold at Fort Oswego, seizing and taking control of the position over the course of the week beginning August 10, 1756. The fort itself stood where Oswego, New York, exists today.

Montcalm's victory yielded not only 1,700 captured soldiers but also control of 121 cannons that had defended the fort. This defeat essentially ended British influence on Lake Ontario for the time being, eliminating any danger the garrison might have posed to Fort Frontenac, which remained under French control nearby. What made this engagement particularly significant was its proof that conventional European approaches to siege warfare could succeed on American soil, provided they were executed with skill and matched to the surrounding conditions and landscape.

Background

The clash at Jumonville Glen in 1754 marked the opening of hostilities between French and British colonists, prompting both crowns to dispatch regular soldiers to North America. These forces aimed to settle competing claims over the Ohio Country and other contested borderlands, among them the boundary separating French Canada from the British province of New York, a region now known as Upstate New York that the Iroquois nations largely controlled at the time. Among Britain's objectives for 1755 was a planned campaign to seize Fort Niagara, positioned at Lake Ontario's western edge. Massachusetts Bay governor William Shirley oversaw the strengthening of the existing Fort Oswego and the construction of two new strongholds, Fort George and Fort Ontario, both completed in 1755. Logistical obstacles ultimately scuttled the Niagara campaign, leaving the Oswego defenses staffed through the winter months of 1755 and 1756.

France held naval superiority on Lake Ontario in 1755, its large vessels traveling unopposed between Fort Niagara to the west and Fort Frontenac near the Saint Lawrence River's head. That advantage enabled a French winter assault in March 1756 against Fort Bull, situated on Wood Creek. This outpost served as a crucial depot along the supply route to Oswego, a path running up the Mohawk River before connecting to the Oswego River system. The raid succeeded in destroying substantial provisions meant for the Oswego garrison, effectively dooming Shirley's hopes of renewing the Niagara expedition in 1756. Acting on instructions from New France's governor, Pierre François de Rigaud, Marquis de Vaudreuil-Cavagnal, French and native raiding parties commanded by Louis Coulon de Villiers began tormenting Oswego's defenders starting in May 1756, operating from a base at Henderson Bay south of what is now Sackett's Harbor, New York.

May 1756 also brought General Louis-Joseph de Montcalm to Montreal to take charge of French army units. His relationship with Governor Vaudreuil soured almost instantly, the two clashing repeatedly over questions of authority. Worried by British troop concentrations near the southern shore of Lake George, Montcalm traveled first to Fort Carillon on Lake Champlain to inspect its defensive readiness. Meanwhile Vaudreuil began gathering forces at Fort Frontenac, contemplating a strike against Oswego. Encouraging news from the raiding parties eventually convinced both men to commit to the attempt.

News reached Shirley in March 1756 that John Campbell, 4th Earl of Loudoun, would replace him as governor. General James Abercrombie, serving as Loudoun's deputy, did not reach Albany until late June, giving Shirley time to strengthen the Oswego supply line while preparing to lead his own assault on the French Lake Ontario forts. That June, William Johnson journeyed to the Iroquois council at Onondaga, securing pledges of assistance from the Iroquois, Shawnee, and Delaware peoples, forces Shirley intended to incorporate into his own plans. Shirley additionally recruited 2,000 armed "battoemen," skilled boatmen and shipbuilders. Led by John Bradstreet, this group managed to resupply the Oswego forts in July, though a French raiding party ambushed them during their return journey, inflicting between 60 and 70 casualties. Loudoun's arrival in Albany at the end of July brought an immediate halt to Shirley's Oswego expedition plans.

Three distinct forts comprised the Oswego defensive complex. Fort Ontario stood on the river's eastern bank, a log structure built in 1755 atop high ground commanding the river mouth, kept in reasonably sound condition and defended by 370 troops from Pepperrell's Regiment. West of the river sat Fort Oswego, its stone and clay core ringed by earthworks facing south and west, though entirely vulnerable to fire from Fort Ontario across the water. Fort George, newly built and derisively dubbed "Fort Rascal" by soldiers of Shirley's Regiment stationed at Fort Oswego, remained an unfinished wooden palisade without even loopholes for defenders to shoot through, held by 150 New Jersey militiamen. Neither of the latter two forts offered much protection for their garrisons, and cannons were scarce across

Aftermath

Roughly 1,700 people surrendered on the British side, a group that included laborers, shipbuilders, and women and children alongside soldiers. Montcalm withheld the honours of war from the defeated garrison, believing that Littlehales had not fought hard enough to deserve such treatment. Once Canadian militia and Indians gained entry to the fort, chaos followed as they plundered its contents, broke open rum barrels, and drank themselves into intoxication.

In the disorder that ensued, several British soldiers attempted to flee but were caught and tomahawked by intoxicated French troops or Indians. A band of Abenakis seized Colonel Littlehales and beat him severely, accusing him of cowardice and poor conduct during the fight. Montcalm, disturbed by what he witnessed, managed eventually to halt the violence, though he estimated the incident would cost the King somewhere between eight and ten thousand livres in gifts meant to smooth things over. Afterward he had the remaining supplies and unfinished boats destroyed, and the whole company, prisoners included, set out for Montreal.

Not until August 12 did Loudoun finally send reinforcement troops, drawn from the 44th Regiment of Foot along with Bradstreet's battoemen, in the direction of Oswego. By the time these forces arrived at the Oneida Carry, word reached them that Oswego had already fallen. They tore down the fortifications there before withdrawing to German Flatts, where Loudoun instructed them to remain and guard against any further French movement. In the months that followed, Loudoun devoted considerable energy to placing responsibility for the defeat on William Shirley. An inquiry ultimately cleared him of formal wrongdoing, though it revealed a number of irregularities in his conduct. Thanks to his political ties in London, Shirley went on to secure other favorable appointments later in his career.

Oswego remained largely deserted until the British moved back into the area in 1758, when Bradstreet launched a campaign that ended with the capture and destruction of Fort Frontenac. The site served again in 1759 as the starting point for a successful campaign against Fort Niagara, and once more in 1760 when Jeffery Amherst's forces passed through on their advance toward Montreal.