The schooner in the distance made Enoch Parrott, commander of the USS Perry suspicious. Standing aboard ship in the late afternoon of June 3, 1861, he observed a schooner trailing a brig. Parrott suspected the schooner might be a Confederate privateer, and it seemed to him the brig was its intended prey. It would make sense; this patch of ocean 60 miles off Charleston was prime real estate for Confederate raiders.

By this early juncture in the Civil War, privateers were a concern for the U.S. Navy and northern businessmen reliant on shipping. Nearly two months before, just after the fall of Fort Sumter, Confederate President Jefferson Davis announced he would begin issuing letters of marque to privately armed vessels, effectively sanctioning piracy as legal.

Largely forgotten today, letters of marque are an old stand-by for fledgling nations with no navy. Governments would issue the letters to private owners of armed ships who would take to the sea and raid enemy shipping. The ship owners would receive no remuneration from the government, but could keep whatever loot they captured.

During the American Revolution and the War of 1812, the U.S. government issued the letters to muster a force against the formidable Royal Navy. So important was it to national defense that the writers of the Constitution included it as one of the enumerated powers of Congress, along with taxation and the right to declare war.

Upon hearing the news of Davis’s declaration, Edmund Ruffin, a South Carolina secessionist and an astute political observer, noted in his diary, “The enactment of issuing commissions to privateers…[is an] important means of defence, especially in our peculiar circumstances, of having almost no ships, or ocean commerce.”

After Davis’s declaration, concern quickly grew among northern shipping directors. Privateers were dangerous and could threaten the free passage of ships overseas. As a countermeasure, Lincoln ordered a blockade of Southern ports, and included “pretended letter of marque,” as one of his reasons.

The Perry was on blockade duty off Charleston and Parrott ordered his ship to close in on the schooner, which turned and fled. The Perry gave chase and fired a shot across the schooner’s bow. The ship halted and raised a flag, but in the darkness, Parrott could not see it. The Perry fired at the schooner directly and the privateer returned fire, but within 20 minutes it surrendered.

A party boarded the schooner and arrested 14 men and they were taken to New York City to stand trial as pirates. The jury, however, failed to reach a verdict. But in Philadelphia, a separate privateer crew was sentenced to hang.

Days later, the Confederate congress authorized Davis to execute an equal number of Union prisoners if the North harmed any privateers. When Lincoln heard of the threat he postponed the executions indefinitely. Eventually, the privateers from both ships were exchanged for Union prisoners of war.