Which American Revolutionary War battle helped persuade France to openly ally with the United States?

The Battle of Saratoga helped persuade France to openly ally with the United States during the American Revolutionary War.

The Saratoga campaign culminated in the surrender of British General John Burgoyne's army to American forces under General Horatio Gates on October 17, 1777. The victory demonstrated that the American rebellion could defeat a major British field army rather than merely conduct local resistance.

France had already provided secret assistance to the American cause, including supplies and weapons. After Saratoga, France formally recognized the United States and signed the Treaty of Amity and Commerce and the Treaty of Alliance in 1778. French military and naval support later became crucial to the American victory.

Saratoga is often called a turning point, but it did not end the war. Fighting continued for several years, and the final British surrender came at Yorktown in 1781. Saratoga's importance was diplomatic as well as military because it brought a powerful European ally openly into the conflict.