Because it lacked sufficient funds to build a strong navy, the Continental Congress gives privateers permission to attack any and all British ships on April 3, 1776.
In a bill signed by John Hancock, its president, and dated April 3, 1776, the Continental Congress issued "INSTRUCTIONS to the COMMANDERS of Private Ships or vessels of War, which shall have Commissions of Letters of Marque and Reprisal, authorizing them to make Captures of British Vessels and Cargoes."
Letters of Marque and Reprisal were the official documents by which 18th-century governments commissioned private commercial ships, known as privateers, to act on their behalf, attacking ships carrying the flags of enemy nations. Any goods captured by the privateer were divided between the ship’s owner and the government that had issued the letter.
Congress informed American privateers on this day that "YOU may, by Force of Arms, attack, subdue, and take all Ships and other Vessels belonging to the Inhabitants of Great Britain, on the high seas, or between high-water and low-water Marks, except Ships and Vessels bringing Persons who intend to settle and reside in the United Colonies, or bringing Arms, Ammunition or Warlike Stores to the said Colonies, for the Use of such Inhabitants thereof as are Friends to the American Cause, which you shall suffer to pass unmolested, the Commanders thereof permitting a peaceable Search, and giving satisfactory Information of the Contents of the Ladings, and Destinations of the Voyages."
The distinction between pirates and privateers was non-existent to those who faced them on the high seas. They behaved in an identical manner, boarding and capturing ships using force if necessary. However, privateers holding Letters of Marque were not subject to prosecution by their home nation and, if captured, were treated as prisoners of war instead of criminals by foreign nations.