Acting independently and without approval of Congress, the President in September 1940, turned over to the Royal Navy fifty over-age American destroyers in an effort to make up for the ravages of German submarines against the North Atlantic convoys. In return the British government gave on a ninety-year lease the rights to naval and air bases in British colonies in the Caribbean, Guiana, Newfoundland and Bermuda. The agreement, in President Franklin D. Roosevelt's words, was "the most important action in the reinforcement of our national defense that has been taken since the Louisiana Purchase."