In a hundred and forty years, more or less, the French had made wonderful progress in opening up the interior of North America to exploration and trade; they had founded settlements at the extremities of their dominion on the St. Lawrence and the lower Mississippi, and had connected these by a chain of forts on the Great Lakes and the northern tributaries of the Mississippi; but they had established only one strong colony in the interior, the settlement at Detroit. As the middle of the eighteenth century approached, they awoke to the need of making good their claim to the Ohio Valley, building a line of forts at Presque Isle on Lake Erie, Le Bœuf, Venango, and Duquesne, on the route from that lake to the Ohio River. They also strengthened themselves by erecting a fort on the southern shore of Lake Erie at Sandusky, about halfway between Cleveland and Detroit. The energy of the French was in part due to the exhibition of an intention of the English to enter the great interior basin; but the French activity aroused the English, and in 1754 the final contest for the control of the continent began in the western wilderness of Virginia and Pennsylvania. With the war elsewhere, this book has nothing to do; the campaigns for the capture of Duquesne, Louisbourg, Ticonderoga, Quebec, and Montreal, all took place far away from the shores of the Great Lakes; but it was the success of the English in these other fields that determined the fate of the interior. From the beginning the importance of Niagara had been recognized by both combatants, but the strength of its position deferred an attack upon it for several years. In 1758 the English captured Fort Frontenac, and the next summer made a determined attack on Niagara. [Illustration: A View of Niagara Fort, _taken by Sir William Johnson_, on the 25th of July 1759. _Drawn on the Spot in 1758._] The fort at Niagara was now commanded by a French officer and engineer, Captain Pouchot; he had strengthened and enlarged the fortifications and had a garrison of six hundred men well supplied with food and ammunition. The English general, Prideaux, marched with a force of twenty-three hundred men from Oswego and laid siege to the fort. The English engineers opened the trenches so near the fort that they were obliged to withdraw and build a second series. When the artillery was placed in position and opened fire, one of the first shells to be discharged burst prematurely, and a fragment striking General Prideaux on the head, killed him instantly. Sir William Johnson took command in his place and carried on the siege effectively.