Which 1778 treaty formalized the military alliance between the United States and France?

The 1778 treaty that formalized the military alliance between the United States and France was the Treaty of Alliance.

The treaty was signed in Paris on February 6, 1778, by American commissioners Benjamin Franklin, Arthur Lee, and Silas Deane, and by Conrad Alexandre Gérard for France. It was concluded alongside the Treaty of Amity and Commerce, which established commercial and diplomatic relations.

The alliance pledged French military support if Britain attacked France during the continuing war. It also committed both partners to avoid a separate peace with Britain and recognized the importance of preserving American independence. France’s formal involvement transformed the conflict into a wider international war.

French assistance later proved crucial at Yorktown, where French soldiers and naval forces joined Washington’s army. The alliance is sometimes confused with the Treaty of Amity and Commerce because the agreements were signed together. The commercial treaty recognized the United States and established trade relations; the Treaty of Alliance supplied the military framework.