Final answer:
The Second Continental Congress approved the purchase of a fleet of vessels to aid in the American Revolutionary War.
Step-by-step explanation:
The Second Continental Congress, which convened in 1775, approved the purchase of a fleet of vessels to aid in the American Revolutionary War. These vessels were used for various purposes such as transport, blockades, and naval warfare. The exact number of vessels approved for purchase by the Congress is not provided in the given information.