I think you mean the allies.
They gave americans democracy.
It Was the French smartperson.
The native Americans
Help and support from the French.
This question would be clarified immensely if the particular war in question were specified.
The Americans helped the Allies by sending resources to them during WWI.
french allies supplied them with things they needed
actually it is helped kill americans off by eating their flesh
The Americans won beause they wanted their freedom from the British and France see that they can win so they help them.
American help in gaining territory in the Caribbean
How did WHAT help them win the war?
The British defeated the French and most native Americans with the Iroquois help.