The United States was given the right to establish naval bases in the British West Indies during World War II by the British Government in exchange for what?

In 1940, the United States held a neutral position with regard to World War II. Then, France fell to the Germans, and Great Britain was directly in the crosshairs. The United States got nervous and started filling up the coffers for national defense. Meanwhile, German submarines were wreaking havoc on Great Britain's merchant fleet (remember that Britain is an island!), and essential domestic and military supplies were being destroyed.
In late spring, British Prime Minister Winston Churchill sent an urgent appeal to the United States for 50 refurbished destroyers (left over from World War I) to replace losses to her fleet and to help fight the German submarines. Fulfilling the request outright would violate U.S. neutrality laws, but President Roosevelt persuaded Congress to offer a deal to Great Britain: In exchange for the ships, the U.S. would receive 99-year leases for air and naval bases in the British West Indies, British Guiana, Newfoundland, and Bermuda. Great Britain received her ships later that fall, and the U.S. moved closer to war.