Answer:
European countries helped Americans by providing military and economical support. That refers mostly to Spain and France who were British enemies at the time.
Step-by-step explanation:
Spain was mostly engaged in skirmishes in the region of West British Indies, where they were holding British fleet and didn't allow them to help the British forces in colonies. France helped colonists financially from the beginning of the war but officially entered after the battle of Saratoga. At the end of the war the peace treaty was even signed in Paris.