France signed the first formal alliance with the United States during the Revolutionary War.
The Treaty of Alliance was signed in Paris on February 6, 1778. It joined France and the United States in a defensive and commercial partnership against Great Britain. The agreement followed the American victory at Saratoga, which convinced France that the new republic had a credible chance of surviving.
France supplied arms, money, troops, and naval forces. French assistance was especially important at Yorktown, where the French fleet prevented a British evacuation by sea while American and French armies surrounded General Cornwallis’s forces.
The alliance was not simply an act of friendship. France was also seeking revenge for its defeat by Britain in the Seven Years’ War and wanted to weaken British power. Spain entered the war against Britain in 1779 but did not sign the same type of formal alliance with the United States.