Well, uniting against a common enemy has always been a great unifier. Plus, literally fighting for freedom made every person fighting believe very deeply in their cause, and so they could overcome differences with each other for that cause.
Assuming you're referring to the American Revolution, the revolutionaries felt they were in danger because the British far outmatched them in terms of man power and skill. To remedy this the colonists turned to foreign aid, especially from the French.
Samoset traded and was friendly and introduced Squanto who was basically the right hand man to a chief who facilitated peace with the pilgrims.
18 percent of people in Switzerland are French.
