Franklin was able to secure treaties of commerce and alliance. Even before this, many French volunteers had sailed to America. The most prominent among them was the Marquis de La Fayette, a young army officer, who, in the winter of 1779-80, went to Versailles and persuaded his government to make a real effort to bring the war to an end. Soon afterward, Louis XVI sent to America an expeditionary force of 6,000 men under the Comte de Rochambeau. In addition, the French fleet aggravated the difficulties the British were having in supplying and reinforcing their forces, and Frenchmen joined with American blockade runners in inflicting severe losses on British commerce.
In 1778, the British were forced to evacuate Philadelphia because of threatened action by the French fleet. During the same year, in the Ohio Valley, they suffered a series of setbacks which assured American