The _causes_ of the war grew out of the encroachments of the French upon the frontier of the English colonies in America. Such, at least, was the allegation on the part of England. France had established settlements on the St. Lawrence, and at the mouth of the Mississippi, and commenced the gigantic plan of uniting these points by a chain of forts, extending across the continent, and designed to confine the English colonists to the eastern slope of the Alleghanies. The French possessed considerable military strength in their northern colonies. They had strongly fortified Quebec and Montreal, and, at other points, the frontiers were defended by Louisburg, Cape Breton, and the forts of Lake Champlain, Niagara, Crown Point, Frontenac, and Ticonderoga. And they had, also, a fort of some strength at Du Quesne, now the spot on which Pittsburg is built. The establishment of French posts on the Ohio, and the attack on Colonel Washington, were declared, by the British government, as the commencement of hostilities. The French, however, allege the intrusion of the Ohio Company upon their territory, as the immediate cause of the war. General Braddock, at the head of fifteen hundred troops, had been despatched to America. On his arrival in Virginia, he requested a convention of colonial governors to meet him there, to confer on the plan of the ensuing campaign. They accordingly met, and three expeditions were resolved upon--one against Du Quesne, to be conducted by General Braddock; one against forts Niagara and Frontenac, to be commanded by Governor Shirley; and one against Crown Point, to be led by General Johnson. The last-named expedition was a measure proposed by Massachusetts, and was to be executed by troops raised in New England and New York. In the mean time, a fourth expedition, which had been previously concerted, was carried on against the French forts in Nova Scotia. This province, it seems, after its cession to the English, by the treaty of Utrecht, was still retained, in part, by the French, as its boundaries were not defined. They had built forts on a portion of it which the English claimed. To gain possession of these, was the object of the expedition. About two thousand militia, under Monckton and Winslow, embarked at Boston, on the 20th of May, 1755; and, having been joined by three hundred regulars, when they had arrived at Chignecto, on the Bay of Fundy, they proceeded against Beau Sejour, now the principal post of the French in that country. This place they invested and took possession of, after a bombardment of a few days. Other forts were afterwards attacked and taken, and the whole province was secured to the British, according to their idea of its proper boundaries.