France was the United States’ principal European ally during the American Revolutionary War.
French assistance began with covert supplies and financial support before France formally recognized the United States. The two countries signed the Treaty of Alliance in 1778, after the American victory at Saratoga demonstrated that the rebellion had a realistic chance of success.
France provided weapons, uniforms, money, soldiers, sailors, and naval power. French troops fought alongside American forces, while the French fleet challenged British control of the Atlantic and the American coast. French support placed Britain in a wider global war involving European and overseas theaters.
French military and naval participation was especially important at the Yorktown campaign in 1781. The French fleet helped prevent a British evacuation or reinforcement by sea, while French troops joined Washington’s army on land. Yorktown’s surrender became the decisive military turning point, although fighting continued afterward. Spain and the Dutch Republic also opposed Britain in different ways, but France was the central formal ally of the American revolutionary cause.