France became the United States’ formal wartime ally in 1778 during the Revolution linked to America250.
The Treaty of Alliance was signed in Paris on February 6, 1778, alongside a Treaty of Amity and Commerce. France recognized the United States and agreed to support it against Britain. The alliance followed the American victory at Saratoga, which convinced French leaders that the rebellion had a realistic chance of succeeding.
French assistance included money, weapons, military supplies, naval support, and troops. French naval operations were especially important at Yorktown in 1781, where the fleet helped prevent British reinforcements and contributed to the surrender of General Cornwallis’s army.
France’s participation greatly internationalized the conflict. Spain later entered the war against Britain but did not sign the same formal alliance with the United States. The French alliance also deepened the financial pressures that contributed to France’s later political crisis.