In 1940 an important precedent was established for wide-ranging executive agreements by President Roosevelt's transfer of 50 antiquated destroyers in exchange for a series of long-term base rights in the Western Hemisphere.
Langenberg, William H.
"Destroyers for Naval Bases: Highlights of an Unprecedented Trade,"
Naval War College Review: Vol. 23
, Article 10.
Available at: http://digital-commons.usnwc.edu/nwc-review/vol23/iss5/10