The Two Sieges of Louisbourg: Harbingers of American Discontent

Prewar Conflict (<1775)

November 30, 2021
by David O. Stewart Also by this Author


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When they heard the news in 1757, some New Englanders smirked. Others grew angry.

The British were mounting a major expedition against the powerful French fortress at Louisbourg on Cape Breton Island, next to Nova Scotia. Sometimes called “the Gibraltar of the North,” Louisbourg was the key to the French empire in North America. New Englanders had seized it a decade before, but then the British gave it back in a peace settlement, tossing the fortress away. Now the British had to capture it all over again.

In 1757, Britain and France were at war for the third time in sixty years. When the previous conflict—the War of the Austrian Succession—spread to North America, Louisbourg loomed as the gateway to New France. Built over a twenty-five-year period, the stone walls of the fortress reached thirty feet high, spread thirty-six feet thick at their base, and boasted defensive embankments, ditches, angled fields of fire, and artillery batteries.[1]

Ships sheltered in Louisbourg’s large harbor could command access to the St. Lawrence River, which rose from the Great Lakes in the heart of the continent, then flowed past Montreal and Quebec. Louisbourg-based ships also could patrol the fish-rich Grand Banks, which had drawn European fishing fleets for centuries.[2]

Round One

In the previous decade, British war planners had ignored Louisbourg when conflict with France spread across Europe, through the rich sugar colonies of the Caribbean, even in the Indian Ocean. When the war began in 1744, North America did not rank high on London’s agenda.

But for New Englanders, the French fortress threatened trade, fishing, even survival, while the French Catholic faith stirred deep religious hostility. In early 1745, the colonists persuaded the Massachusetts royal governor, Sir William Shirley, to sponsor an expedition by colonists, not by the British military, to take Louisbourg. To lead the effort, Shirley chose a merchant from the colony’s Maine district, William Pepperell, who had no military experience whatever. By late March, Pepperell was leading a force of four thousand colonists in ninety transports—mostly fishing sloops and schooners redolent with the aromas of the season’s catch—bound for Cape Breton Island.[3]

After this brisk beginning, the 1745 campaign against Louisbourg proved grueling. Though the colonists were buoyed by the last-minute decision by a British squadron commander to bring his warships to bear against the mighty fortress, they had too few men and too little firepower. As Benjamin Franklin in Philadelphia warned his brother in Boston, “Fortified towns are hard nuts to crack, and your teeth are not accustomed to it.”

So the Americans improvised. They captured powerful French artillery batteries and turned them around to fire against the men who had built them. Hundreds of colonists harnessed themselves like oxen to drag whaleboats and naval cannons across Cape Breton’s rocky fields and through knee-deep marshes, then mounted surprise attacks on French weak points. After two months of unremitting effort, the unlikely invaders won the fortress.[4]

The tremendous effort brought the colonists mostly dismay, despair, and disappointment. Forced to occupy the remote fortress through a harsh winter until British troops arrived, hundreds of colonists died of dysentery and other diseases. By one estimate, deaths from disease topped one thousand, roughly ten times the American deaths in battle.

The summer of 1748 brought the British betrayal. The Treaty of Aix-la-Chapelle restored Louisbourg to the French; in return, the French relinquished control of lands it had won in Flanders.[5]

When news of the peace terms reached Boston, a twenty-six-year-old newspaper editor named Samuel Adams, already a rabble-rouser, reached for his pen. He denounced the patronizing treatment of colonial soldiers by their British overlords and objected that British sailors, but not American colonists, were enriched by prizes taken from the French at Louisbourg. Beholding “the Fruits of all our Labours, Toils and Hazards, given up at once to our proud insulting Enemies,” Adams feared that the perfidious British would abandon the colonists entirely, adding that “the Mind opprest with Grief, anxious and fearful, cannot help raising to itself most frightful Prospects.”[6]

Round Two

Having learned that their massive fortress could be taken, the French rebuilt it and strove to improve its harbor defenses. After only a few years of peace, the old rivals slid back into their global struggle for dominance. After the Seven Years’ War was declared in 1756, the British targeted Louisbourg. The large harbor on Cape Breton Island still could shelter warships that disrupted fishing on the Grand Banks and intercepted coastal traders that were essential to colonists in Maine, New Hampshire, Massachusetts, and Rhode Island.

This time around, the British seized the initiative, aiming to mount an expedition of mostly British forces. The assault would not be led by American merchants nor mostly fought by citizen soldiers. This time, the commanders would be professionals like Gen. Jeffrey Amherst and the dashing Gen. James Wolfe, who soon would win fame by giving his life in the successful assault on Quebec. Even for the professionals, however, Louisbourg remained a tough nut to crack.

The initial planning by Lord Loudoun, British commander in North America, consumed so much of the 1757 fighting season that the expedition was postponed for a year. The delay was business-as-usual for Loudoun, whose reputation for inaction was matched by his great wealth and notable corpulence. Franklin drolly compared Loudoun to “St. George on a tavern sign, always on horseback and never rides on.”[7]

By June 1 of the next year, a British fleet of 37 warships and 120 transports approached Louisbourg. It carried 12,000 soldiers, only a few hundred of whom were colonists. General Wolfe sniffed dismissively that the Americans were “little better than canaille” (scoundrels). His contempt for the Americans did not stop Wolfe from copying their tactics in the last assault on Louisbourg, choosing to bypass the powerfully-defended harbor and land his troops at Freshwater Cove. Many British landing craft wrecked on Cape Breton’s rocks and boulders while French troops awaited onshore. Staggering up from the surf, Wolfe’s waterlogged men still managed a flanking maneuver that sent the French scurrying back to their fortress.[8]

Once ashore, the British employed the siege tactics of eighteenth century military engineers. They unloaded cannons from their warships and dragged them into position before the fortress, then began a constant bombardment from land and sea. Soldiers became sappers, spending their days digging trenches and artillery fortifications ever closer to the fortress walls. Each time they dragged the cannons forward and installed them in new tranches, the cannoneers blazed away at the walls with ever-greater effectiveness. Then the diggers and artillerymen did it all over again. And then again.

French forces occasionally sallied forth, hoping to ambush British units and disrupt the relentless digging. But as the attackers’ guns crept closer, the impact of their fire increased and the fortress walls weakened. As long as the besiegers’ ammunition, men, and supplies held out, the town would fall. Because British fleets had twice blocked French naval squadrons from crossing the Atlantic and relieving Louisbourg with men and supplies, the forces trapped in the fortress had no hope.[9] A French officer’s diary describes the grim scene inside the fortress:

From yesterday morning till seven o’clock this evening we reckon that a thousand or twelve hundred bombs, great and small, have been thrown into the town, accompanied all the time by the fire of forty pieces of cannon . . . The hospital and the houses around it, which also serve as hospitals, are attacked with cannons and mortars . . . The sick and wounded, stretched on mattresses, utter cries of pain, which do not cease till a shot or the bursting of a shell ends them.[10]

During the siege of Louisbourg in 1758, the British set fire to the French vessel le Prudent, left, and captured le Bienfaisant, right. (Wikimedia Commons)

After weeks of unceasing bombardment, British shells ignited three French ships of the line in the harbor, each carrying sixty-four guns. The French warships burned to the waterline. A daring British raid captured two other French ships.

By the end of June, after seven weeks of siege, the walls of the French fortress were crumbling and the defenders had only four functioning cannon left. The garrison surrendered.[11] For the second time in eleven years, the supposedly impregnable fortress fell to France’s mortal enemy.

This time, the British chose to consolidate their North American empire through the peace negotiations, reversing their policy in the previous treaty with France. Under the Treaty of Paris of 1763, Britain not only retained the Louisbourg fortress, but also acquired all of what became Canada; Spain acquired the French claim to trans-Mississippi lands.

A leading British official sniffed at the Caribbean sugar island of Guadalupe as a “trifling object” compared to the vast new trade opportunities that would open from acquiring Canada. In contrast, a shrewd Frenchman, the Duc de Choiseul, snickered over the British strategy reversal, predicting that France’s global rival would soon lose North America to an internal rebellion.[12]

A decade later, Samuel Adams of Boston and some unruly New England tax resisters would light the fire that confirmed the Frenchman’s prophecy.


[1]Robert Emmet Wall, Jr., “Louisbourg 1745,” New England Quarterly 37:64, 65-66 (1964); J. Revell Carr, Seeds of Discontent: The Deep Roots of the American Revolution, 1650-1750, New York: Walker & Co. (2008), 119-22.

[2]Thomas Pichon, Lettres et Memoires pour Servir a l’histoire naturelle, civile et politique du Cap Breton, etc. (London: Jean Nourse, 1760), 9-10.

[3]Ibid., 194, 204; John F. Ross, War on the Run: The Epic Story of Robert Rogers and the Coquest of America’s First Frontier (New York: Bantam, 2009), 36-37. A precise count of the men and ships on this expedition is lacking. One source describes it as involving 5,000 men and sixty-three ships. Thomas P. Slaughter, Independene: The Tangled Roots of the American Revolution (New York: Hill and Wang, 2014), 58.

[4]Benjamin Franklin to John Franklin, May 1745 (?), in Papers of Benjamin Franklin, Founders Online.

[5]Douglas Edward Leach, “Brothers in Arms? Anglo-American Frictionat Louisbourg, 1745-1746,” Proceedings of the Mass. Hist. Soc., 89:36 (1977); Jack M. Sosin, “Louisbourg and the Peace of Aix-la-Chapelle,” William & Mary Quarterly 14:516 (1957); M.S. Anderson, The War of the Austrian Succession, 1740-1748 (London: Longman, 1995), 202-04; Slaughter, Independence, 63.

[6]Peter Bower, Louisbourg: A Focus of Conflict,H E 13, in Parks Canada, “Researching the Fortress of Louisbourg National Historic Site of Canada” (March 1970),; Carr, Seeds of Discontent, 310-12.

[7]Ross, War on the Run, 139; The Autobiography of Benjamin Franklin (Boston: Houghton Mifflin & Co., 1888), 208.

[8]Robert Leckie, “A Few Acres of Snow”: The Saga of the French and Indian Wars (New York: John Wiley & Sons, 1999), 306-07; Hugh Boscawen, The Capture of Louisbourg, 1758 (Norman: University of Oklahoma Press, 2013).

[9]Fred Anderson, Crucible of War: The Seven Years’ War and the Fate of Empire in British North America, 1754-1766 (New York: Alfred A. Knopf, 2000), 251-53, 257-58.

[10]Ibid., 308.

[11]Anderson, Crucible of War, 254.

[12]Slaughter, Independence,183; W.J. Eccles, “The Role of the American Colonies in Eighteenth-Century French Foreign Policy,” in W.J. Eccles, Essays on New France (Toronto: Oxford University Press, 1987), 141-55. Choiseul’s insight was embraced by France’s leading diplomat, the Count de Vergennes, who warned that “Delivered from a neighbor they have always feared, your other colonies will soon discover that they stand no longer in need of your protection. You will call on them to contribute toward supporting the burden which they have helped to bring on you, they will answer your by shaking off all dependence.” Leckie, “A Few Acres of Snow,”365.


  • I am disappointed that such an eminent scholar as David Stewart could have gotten the Louisbourg story so wrong. As Gov. William Shirley knew, the war that included the 1745 capture of Louisbourg was a desperate French attempt to overcome near bankruptcy by seizing British colonies in India and America. Shirley had the advantage of a complete plan of the Louisbourg fortification, courtesy of architect Peter Harrison (a former POW there).
    Louisbourg was not traded for anywhere in Flanders but for most of India, a VERY good trade.
    The war that included Louisbourg II was inevitable because the French had not improved their finances and still needed to capture British colonies. That war broke out only a short time after the 1748 treaty, both in India and Pennsylvania in the early 1750s. The British, thanks to George Anson, had improved their navy in order to deal with any future French problems.

  • This article barely skim the surface of these two sieges and offers only an English-centered view of events with oversimplification of acts. For a far more balanced and detailed study of the second siege of Louisbourg, you may wish to consult “Endgame 1758: The Promise, the Glory and the Despair of Louisbourg’s Last Decade” by former Parks Canada historian A. J. B. Johnston, published by University of Nebraska Press in 2007.

  • For more than three centuries British foriegn policy was based on denying French and later German control of the low countries. This was due to the perceived strategic threat that a major power could use Flanders as a base from which to launch a surprise cross channel invasion thereby necessitating the retention of a large standing army in southern England. Essentially the cuban missile crisis for Georgian Britain. Sefishly for the British retaining Louisbourg was nowhere near that kind of priority.

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