Which 1777 American Revolutionary War victory helped persuade France to ally with the United States?

The 1777 American Revolutionary War victory that helped persuade France to ally with the United States was the Battles of Saratoga.

The Battles of Saratoga were fought in New York on September 19 and October 7, 1777, during the Saratoga campaign. American forces under General Horatio Gates opposed the British army commanded by General John Burgoyne. After the second battle, Burgoyne’s army was surrounded and surrendered on October 17.

The surrender demonstrated that the American cause could defeat a major British force. France had already provided some covert assistance, but the news from Saratoga encouraged King Louis XVI’s government to negotiate openly with the Americans. The resulting Treaty of Alliance was signed on February 6, 1778, formally bringing France into the war as an American ally.

A common mix-up is calling Saratoga a single battle. Historians generally refer to two engagements—Freeman’s Farm and Bemis Heights—as the Battles of Saratoga. The victory is also distinct from Yorktown, where British General Cornwallis surrendered in 1781.