France was the principal foreign ally of the American revolutionaries. French military, financial, and naval support played a major role in the American victory over Great Britain.
France formally entered the war in 1778 after the American victory at Saratoga. The Treaty of Alliance committed France to support the United States, while the Treaty of Amity and Commerce opened commercial relations. French troops and ships later fought alongside American forces, most decisively during the Yorktown campaign.
Spain and the Dutch Republic also opposed Britain and supported the American cause in different ways, but France was the central formal ally. French assistance came partly from strategic rivalry with Britain, which had defeated France in the Seven Years’ War. The alliance helped transform the colonial rebellion into a wider international conflict.