2. Congress began issuing letters of marque in 1776
Letters of marque were documents issued to privately owned ships designating them as legally able to prey upon the ships of belligerent nations in time of war. The ships, known as privateers, were authorized to capture or destroy enemy shipping. They preferred to capture them, because if they were able to make it to a friendly port the ships and cargoes were sold, with the proceeds being awarded to the privateer’s owners and crews. Fortunes could be made in privateering, and many of the great names of England’s naval history, including Sir Francis Drake and Sir Walter Raleigh, had served as privateers.
The lure of prize money made privateering much more attractive to sailors than service in the Navy, where discipline was tougher, pay lower, and the prospects of doing battle with the Royal Navy more likely. Privateers thus had an advantage when attracting sailors for cruises, and successful captains often reported the amount of prize money earned on earlier cruises. For the most part, privateer captains turned tail when encountering a British warship at sea, and often out-sailed them to safety. When France and later Spain entered the war, they too issued letters of marque, and the British were forced to use more and more ships to escort their merchant fleets.