After the treaty of Aix-la-Chapelle finished that earlier war, the hatred between the French and the English in the Americas never quite waned. It must be understood, that in 1755 France held most of America. The French land claims covered Canada (close to what we know know as Canada), as well as New France (that is, the stretch of land following the Mississippi River all the way to Louisiana).
The English, wanting to expand their land, often moved into the land claimed by the French. This encroachment forced the French to build several forts along the frontier. Some of these forts were Fort Duquesne (Near present day Pittsburgh), and Fort Miamis. The French, never lovers of the English due to hundreds of years of fighting, sent the Indians who allied themselves with the French in raiding parties in retaliation for raids conducted by the Indians on the English side, who claimed that thier raids were in retaliation for those made by the French. It didn't matter which side was correct, the main object wasn't to retaliate, but rather for the French to keep the English in their place, and for the English to iritate the French as much as possible until they moved out.
With the tensions already riding high, the French began to build litle Fort Le Boeuf downriver from Fort Duquesne, near Lake Erie. The English at this time claimed this land as their own. After some debate, the English decided to send a certain Major George Washington to the region of Fort Duquesne and evict the French. Washington, then 22 years old, headed a small party through the woods. While advancing, he came upon a party of French who were probably scouts. Washington gave the order to fire, and in the battle that ensued 10 French were killed, and some 22 captured. This, of course, was at a time of official peace. Washington was accused by the French of coldly leading an assasination of those men who were killed, and in fact even tricked Washington into signing a document that was translated into saying that he had attacked the party. In fact, the document he signed stated that he had Assasinated, rather than Attacked the party.
For movie buffs, it was this part of our history that was dramatized so beautifully in "The Last of the Mohicans".
The French instigated their Indian allies to attack settlers all along the frontier. This they did in a most brutal fashion. Please note, all the bleeding hearts for Indians.