Which Revolutionary War battle helped persuade France to ally with the American colonies?

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

The Saratoga campaign culminated in the American victory at the Battles of Saratoga in October 1777. British General John Burgoyne surrendered his army to American forces commanded by General Horatio Gates, with Benedict Arnold also playing a major battlefield role before later changing sides.

The victory demonstrated that the American rebellion could defeat a major British field army. France had already provided covert assistance, but Saratoga convinced the French government that an open alliance might be strategically worthwhile. The Treaty of Alliance and Treaty of Amity and Commerce were signed in February 1778.

Saratoga did not end the war. French military and naval support later proved important, especially during the Yorktown campaign in 1781. Yorktown was the decisive final major campaign, while Saratoga is remembered as the turning point that brought France openly into the conflict.