The United States occupied the central area of the Rhineland along the Mosel river and the Koblenz bridgehead. General John J. Pershing, commander of the American Expeditionary Forces (A. E. F.), created the Third US Army for this purpose, giving the command to Major General Joseph T. Dickman. In early 1919, the Third Army comprised some 250,000 men.[3] The Americans opened their headquarters in a Prussian government building by the Rhine in Koblenz.