Colonial History Vol.II page 297-299

“Le Salle made many unsuccessful efforts to rediscover the Mississippi. One misfortune after another followed fast, but the leader's resolute spirit remained tranquil through all calamities. At last, with sixteen companions, he set out to cross the continent to Canada. The march began in January of 1687 and continued for sixty days. The wanderers were already in the basin of the Colorado. Here, on the 20th day of March, while Le Salle was at some distance from the camp, two conspirators of the company, hiding in the prairie grass, took a deadly aim at the famous explorer and shot him dead in his tracks. Only seven of the adventurers succeeded in reaching a French settlement on the Mississippi.
France was not slow to occupy the vast country revealed to her by the activity of the Jesuits. As early as 1688 military posts had been established at Frontenae, at Niagara, at the Straits of Mackinaw, and on the Illinois River. Before the middle of the eighteenth century, permanent settlements had been made by the French on the Maumee, at Detroit, at the mouth of the river St. Joseph, at Green Bay, at Vincennes on the Lower Wabash, on the Mississippi at the mouth of the Kaskaskia, at Fort Rosalie, the present site of Natchez, and on the Gulf of Mexico at the head of the Bay of Biloxi. At this time the only outposts of the English colonies were a small fort at Oswego, Lake Ontario, and a few scattered cabins in West Virginia. It only remained for France to occupy the valley of the Ohio, in order to confine the provinces of Great Britain to the country east of the Alleghenies. To do this became the sole ambition of the French, and to prevent it the stubborn purpose of the English.
A second cause of war existed in the long-standing national animosity of France and England. The two nations could hardly remain at peace. The French and the English were of different races, languages, and laws. For more than two centuries France had been the leader of the Catholic and England of the Protestant, powers of Europe. Religious prejudice intensified the natural jealousy of the two nations. Rivalry prevailed on land and sea. When, at the close of the seventeenth century, it was seen that the people of the English colonies outnumbered those of Canada by nearly twenty to one, France was filled with envy. When, by the enterprise of the Jesuit missionaries, the French began to dot the basin of the Mississippi with fortresses, and to monopolize the fur-trade of the Indians, England could not conceal her wrath. It was only a question of time when this unreasonable jealousy would bring on a colonial war.

The third and immediate cause of hostilities was a conflict between the frontiersmen of the two nations in attempting to colonize the Ohio valley. The year 1749 witnessed the beginning of difficulties. For some time the strolling traders of Virginia and Pennsylvania had frequented the Indian towns on the upper tributaries of the Ohio. Now the traders of Canada began to visit the same villages, and to compete with the English in the purchase of furs.