On the French and Indian War: From 1754 to 1763, Britain and France fought for land in North America. Each country had substantial colonial interests (in the "New World") alongside Spain. Britain's lands were primarily coastal with ports extending from what is now Maine down to Georgia. New France's territory included interior lands stretching from Quebec, Canada, past the Great Lakes, and down to the Mississippi Valley. For the most part, British colonists were farmers, which meant they required vast swaths of (cleared) land in order to subsist. On the other hand, French colonists mostly consisted of hunters (fur trappers & traders). Thus, the French colonial lifestyle was more in line with how local Indians were living, including the Iroquois, Mohawk, and Seneca. When violence first erupted between the British and French in Western Pennsylvania, it was only natural for Indians to join the French. In fact, certain British officials like General Edward Braddock were notorious for referring to Indians as "savages," which made British-Indian collaboration (during the war) all but impossible.
