Which 1777 American victory persuaded France to enter the Revolutionary War as a U.S. ally?

The Battles of Saratoga persuaded France to enter the Revolutionary War as an ally of the United States.

The Battles of Saratoga were fought near Saratoga, New York, on September 19 and October 7, 1777. American forces under General Horatio Gates defeated the British army commanded by General John Burgoyne, whose troops surrendered on October 17.

The American victory was strategically important because Burgoyne’s campaign had aimed to divide New England from the other colonies by controlling the Hudson River Valley. His surrender demonstrated that the Continental Army could defeat a major British field force, changing European assessments of the conflict.

France formally entered the war against Britain in 1778. French military aid, money, supplies, and naval power became crucial to the American cause, especially during the Yorktown campaign. The name “Battle of Saratoga” is often used for the whole campaign, but the decisive fighting is generally described as two battles: Freeman’s Farm and Bemis Heights.