The demolition of fort Frontignac and of the stores which had been collected there, contributed materially, to the success of the expedition against fort Du Quesne. The conduct of this enterprise had been entrusted to general Forbes, who marched from Philadelphia, about the beginning of July, at the head of the main body of the army, destined for this service, in order to join colonel Bouquet at Raystown. So much time was employed in preparing to move from this place, that the Virginia regulars, commanded by colonel Washington, were not ordered to join the British troops until the month of September. It had been determined not to use the road made by Braddock, but to cut a new one from Raystown to fort du Quesne. About the time this resolution was formed, and before the army was put in motion, major Grant was detached from the advanced post at Loyal Hannan with eight hundred men, to reconnoitre the fort and the adjacent country. This gentleman invited an attack from the garrison, the result of which was that upwards of three hundred of the detachment were killed and wounded, and major Grant himself was made a prisoner.[163] [Footnote 163: MSS.] [Sidenote: Fort Du Quesne evacuated.] Early in October general Forbes moved from Raystown; but the obstructions to his march were so great that he did not reach fort Du Quesne until late in November. The garrison, being deserted by the Indians, and too weak to maintain the place against the formidable army which was approaching, abandoned the fort the evening before the arrival of the British, and escaped down the Ohio in boats. The English placed a garrison in it, and changed its name to Pittsburg, in compliment to their popular minister. The acquisition of this post was of great importance to Pennsylvania, Maryland, and Virginia. Its possession had given the French an absolute control over the Indians of the Ohio, who were accustomed to assemble at that place, for the purpose of making their destructive incursions into those colonies. Their route was marked by fire and the scalping knife; and neither age nor sex could afford exemption from their ferocity. The expulsion of the French gave the English entire possession of the country, and produced a complete revolution in the disposition of the Indians inhabiting it. Finding the current of success to be running against their ancient friends, they were willing to reconcile themselves to the most powerful; and all the Indians between the lakes and the Ohio concluded a peace with the English.