Congress on April 3, 1776 formally authorized American privateers to raid British merchant ships. In this Congress was merely recognizing what was already well under way, the patriot governments of the various colonies having issued letters of marque and reprisal since the beginning of hostilities. The British parliament would authorize privateers against American merchant ships in December 1776.
Privateers were a traditional part of European naval war which fitted in well with the American national character. Private operations, a common seamen on board a privateer after a successful cruise of capturing several British ships, could come back home with a small fortune in his pocket, often enough to purchase a small farm, or an inn, or set himself up in trade. Privateers led by more daring commanders would even make prizes of several smaller ships of the Royal Navy. Of course the risks were commensurate with the rewards, with death by sinking, or the slow death of rotting away in a British prison hulk if a crew was captured, ever a possibility. Most American sailors were eager to take the risk, so many that the Continental Navy often found it difficult to man its ships.
Some 1,697 American privateers would set sail during the War, capturing an astounding 2, 283 ships, acquiring badly needed supplies for the Continental Army and sending British maritime insurance rates soaring. Some 55,000 Americans served as privateers during the War. About one-fifth of these men lost their lives, either in the deeps of the seas, or as unwilling recipients of the hospitality of His Britannic Majesty after capture. It is likely that the American Revolution could not have been won but for these men who waged a private war afloat.