British Major-General Edward Braddock arrived in Virginia with two regiments of infantry on 14 April 1755. He organized a military expedition to advance into the Ohio Valley and seize Fort Duquesne. His force consisted of 2,100 troops, including 1,400 British infantry and 700 members of the colonial militia. In the first week of June 1755, Braddock's army marched westward.
The Marquis de Vaudrueil, the Governor General of Canada, had not been inactive while the British force assembled in Virginia. He dispatched 817 Canadian militia and Troupes de la Marine to the forts south of Lake Erie. Some 170 Native allies joined the troops as they moved south. By the time Braddock's army had reached the Ohio Valley, the commander of Fort Duquesne, Captain Claude Pécaudy de Contrecoeur, had 72 Troupes de la Marine, 146 Canadian militia, and 637 Native allies at his disposal.
Native and militia scouts had kept Captain Contrecoeur well informed about Major-General Braddock's movements. On the afternoon of 9 June 1755, de Contrecoeur sent one of his officers, Captain de Beaujeu, to set an ambush for the advancing British force. De Beaujeu encountered the advancing British troops, as he was about to deploy his men. Braddock immediately ordered his regulars to form firing lines, but the British infantry found that it was virtually impossible to deploy in the close confines of the woods.
The Canadian force quickly melted into the heavy forest on both sides and deployed along the flanks of the British column. Accurate fire from the Canadians and their Native allies tore into the ranks of the Anglo-American force, and the battle soon became a slaughter. Major-General Braddock was mortally wounded, and 976 British soldiers and colonial militia perished. The Canadian force seized all the British artillery, ammunition, and 500 horses. Captain de Contrecoeur's losses were minimal: 3 officers, 3 militiamen, 2 Troupes de la Marine, and 15 Native warriors. The shattered remnants of Braddock's army straggled back Virginia.