Which 1777 battle helped persuade France to ally with the American revolutionaries?

The Battles of Saratoga helped persuade France to ally with the American revolutionaries in 1777.

The campaign in New York culminated in the surrender of British General John Burgoyne’s army to American forces under General Horatio Gates on October 17, 1777. The American victory demonstrated that the rebellion could defeat a major British army.

France had already been providing limited covert assistance, but Saratoga changed its assessment of the war. In 1778, France formally recognized the United States and entered an alliance with the new country.

Saratoga is often called a turning point of the American Revolutionary War. It is sometimes confused with Yorktown, which was the later decisive siege that led to the British surrender in 1781.