France formed a formal alliance with the United States during the American Revolutionary War.
The Treaty of Alliance was signed in Paris on February 6, 1778, alongside a treaty of amity and commerce. France recognized the United States as a sovereign nation and agreed to support its war against Britain. The alliance followed the American victory at Saratoga, which convinced French leaders that the rebellion had a realistic chance of success.
French assistance included money, weapons, military supplies, troops, naval forces, and diplomatic recognition. The French fleet’s role around Yorktown was especially important because it helped prevent British relief forces from reaching Cornwallis’s army.
France’s intervention imposed major costs on the French government and contributed to financial pressures that later troubled the monarchy. Spain and the Dutch Republic also fought Britain during the wider conflict, but neither was the formal ally named in the 1778 Franco-American treaty. French support was therefore a distinctive foundation of American victory.