France became the first foreign ally of the United States through the Treaty of Amity and Commerce in 1778.
The United States and France signed the Treaty of Amity and Commerce on February 6, 1778. On the same day, they signed the Treaty of Alliance, which created a military partnership against Britain. France had already been providing covert assistance to the American rebels, partly because of its rivalry with Britain and its desire to recover influence after the Seven Years’ War.
The alliance brought important French military, financial, and naval support to the American cause. French troops and ships played a major role in the campaign that culminated at Yorktown in 1781. The alliance was the United States’ first formal treaty relationship with a foreign power.
Spain later entered the war against Britain in 1779, but it did not sign the same alliance treaty with the United States. France’s contribution was therefore distinct from later European assistance and was central to the war’s outcome.