Answer:
The Americans' victory over the British may have been the single greatest impact on the French Revolution. The French people saw that a revolt could be successful – even against a major military power – and lasting change was possible. Many experts argue that this gave them the motivation to rebel.
1. They provided ideological underpinnings. 
2. They posed a heftier geopolitical threat to Britain. 
3. They provided covert aid. 
4. They shared money, men, and material. 
5. They gave the upstart colonists political legitimacy.