The French and Indian War began mainly because of the imperial rivalry between France and Great Britain. Both countries wanted to gain more control over North America. The French and Indian War was the last of a series of wars in the Americas involving France and Britain.
The actual beginning of the war came about because both sides were focusing on the Ohio Valley as a strategic point on the continent. The French needed to keep the Ohio Valley as a way to link their Canadian territories with their territory in the Mississippi Valley. France started to build forts in the area. The colonists tried to build a fort near what is now Pittsburgh. George Washington and a unit of militia went to support the fort. On the way, they got into a skirmish with French soldiers. This was the start of the war.