The eagerness of the French to help the United States was motivated both by an appreciation of the American revolutionaries' democratic ideals and by bitterness at having lost most of their American empire to the British at the conclusion of the French and Indian Wars in 1763.
Negotiated by the American diplomats Benjamin Franklin, Silas Deane, and Arthur Lee, the Treaty of Alliance required that neither France nor the United States agree to a separate peace with Great Britain, and that American independence be a condition of any future peace agreement.
The executive department that deals most with foreign countries is the "State Department", which is headed by the Secretary of State--a position that is appointed by the President.