What was france's role in the american revolution?
They were sent to observe the war and since they saw the outcome of the Saratoga battle (the Colonials won) and that Britain was an enemy of theirs, they helped the colonies defeat the British and eventually win the war. They helped for troops and armies, supplies, money, and trade. Also the Netherlands and Spain, who were French allies, ended up helping too.
Why did France help the colonies in the American Revolution?
They did it to further their own interests. They had an eye on British colonies in the west Indies and had suffered a humiliation when they lost Canada to the British so they had good reasons to help ensure Britain suffered a costly military defeat. In reality however it backfired on them. Their involvement in the war was financially ruinous and that helped to bring about the French revolution and in the long term almost all of their colonies were annexed by the British.