Spring of 1940.
The Destroyers for Bases Agreement was reached in September of 1940. Roosevelt sent destroyer ships to Churchill in exchange for the use of rent free British bases.
British overseas bases.
Likely Churchill.
When Winston Churchill requested a deal that would loan US Navy destroyers to Great Britain, US President Franklin Roosevelt said only by Congressional approval could such a deal be arranged. He also informed Churchill that the time was not yet ripe to even present this the Congress.He was correct. In June of 1940, the Senate amended the Naval Appropriations bill to deny a US president to send war material to any foreign nation unless the Chief of Staff or the Chief of Naval Operations certified that such a provision was required to safe guard the security of the US.
By giving them to an American steel company to then give to the british so he never broke a law doing it this way.
In 1940, Churchill was in dire need for warships. There was the Destroyers for Bases Agreement whereby 50 USN destroyers were transferred to the Royal Navy and the Royal Canadian Navy in exchange for base rights in the Caribbean and Newfoundland. Thus the Americans gave ships to the British and the British gave them base rights return.
Lend Lease US leant destroyers and cargo ships to Britain and charged only a token amount of money. Churchill referred to it as the "most unsordid act in history".
Roosevelt's compromise for helping Britain as he could not sell Britain US destroyers without defying the Neutrality Act; Britain received 50 old but still serviceable US destroyers in exchange for giving the US the right to build military bases on British Islands in the Caribbean.
US Destroyers were built of less than an inch thick of sheet metal. US Battleships, Carriers, and Cruisers had belts of "armor" around them, and were often over an inch thick in sheet metal (skin). Therefore, US Sailors called destroyers, "TIN-CANS"..."Cans" being short for Tin Cans.
In 1940 France had surrendered and Great Britain was in a crisis. Winston Churchill requested that US destroyers be furnished to Britain in exchange for naval base leases. President Roosevelt informed Churchill that such a deal would require Congressional authorization and it would not at that time be a wise decision to request this from the Congress.
Surface warships: Battleships, Cruisers, Destroyers; and US Navy/US Army aircraft.
Gulf of Tonkin