Buoyed by news of the American victory at Saratoga, French Foreign Minister Vergennes told Benjamin Franklin and fellow commissioners that France would recognize American independence and enter formal treaty negotiations. The decision, formalized in treaties signed the following February, brought French money, ships, and troops into the Revolutionary War and transformed a colonial rebellion into a global conflict against Britain.
Franklin had been in Paris since late 1776, cultivating French sympathy for the American cause with a mix of genuine diplomacy and calculated celebrity, appearing in public in a fur cap that made him look like a rustic philosopher straight from Rousseau. France had been quietly funneling supplies to the rebels for two years through a shell trading company, but open recognition risked war with Britain, so Versailles waited for proof the Americans could actually win.
General John Burgoyne's surrender of an entire British army at Saratoga in October 1777 supplied that proof. News reached Paris in early December, and Vergennes moved quickly, aware that Britain might otherwise offer the colonies generous peace terms and end the war before France could benefit from splitting its rival's empire. On December 17, he informed the American commissioners of the King's decision.
The alliance treaties signed on February 6, 1778, committed France to fight until American independence was secured, and brought the Continental Army the naval power it desperately lacked, most decisively at Yorktown in 1781, where a French fleet blocked British evacuation by sea while Washington's and Rochambeau's forces closed the trap on land.