From the US Naval Institute, February 27:
The following are Congressional Research Service Legal Sidebar reports, Letters of Marque and Reprisal: Introduction and Historical Context and Drafting History and U.S. Practice.
From the report
Letters of marque and reprisal were once common tools for countries with small naval forces to augment their militaries by drawing upon the strength of their private merchant vessels. As a young country, the United States used the instruments with success in several early conflicts, including the Revolutionary War and the War of 1812. Over the course of the 19th century, however, commissioning private parties to use armed force fell out of favor in domestic and international practice, and Congress has not authorized a President to issue the instruments since the Civil War. (See CRS Legal Sidebar LSB11273, Letters of Marque and Reprisal (Part 2): Drafting History and U.S. Practice.)
During the era when the United States used letters of marque and reprisal, Congress historically authorized the President to issue the instruments, subject to statutorily defined requirements and conditions, rather than issue instruments directly from the legislative branch. Individual states, by contrast, are prohibited from issuing the instruments under Article I, Section 10 of the Constitution.
The Framers of the Constitution placed the Marque and Reprisal Clause between provisions that authorize Congress to declare war and to “make Rules concerning Captures on Land and Water.” These three authorities are interrelated and can function together. For instance, in conjunction with declaring war, Congress might authorize letters of marque and reprisal allowing private ship-owners to assist the war effort by targeting enemy vessels, as it did in the War of 1812. Holders of those letters could then capture enemy vessels and bring them into port to be condemned and sold as prizes of war. Using its authority to:
“make Rules concerning Captures[,]” Congress could define the legal framework governing how the condemnation proceedings would operate and how the proceeds of the sale would be distributed.
The Supreme Court has mentioned the Marque and Reprisal Clause most frequently when listing Congress’s war powers and authorities over foreign affairs. The Court has described the power to issue letters of marque and reprisal as an inherent feature of sovereignty that is national in nature. The Court has further observed that the Constitution expressly grants Congress the power to issue the instruments and that “no restrictions are imposed” upon that authority. Finally, in an opinion for the Court in Barron v. City of Baltimore, Chief Justice John Marshall observed that the Constitution grants power over the instruments to the federal government while denying states the ability to issue them because, “[t]o grant letters of marque and reprisal, would lead directly to war; the power of declaring which is expressly given to congress.”....
....The Decline of Privateering and Proposals for its Revival
By the latter half of the 19th century, the practice of privateering faded. Commissioning of private parties to use military force increasingly fell out of favor in international practice, and nearly all major European powers renounced the practice. In an 1856 international peace conference, a group of prominent maritime nations issued a declaration, known as the Declaration of Paris, providing that “privateering is and remains abolished.” Critics of privateering cited its negative impact on global trade and humanitarian concerns with privateers’ methods. As one 19th century American commentator on admiralty law stated, privateering was “liable to gross abuses” and “encourage[d] a spirit of lawless depredation” and plundering. Some U.S. officials also expressed these critiques, but President Franklin Pierce declined to sign the Declaration of Paris due to fears that abolishing privateering would provide a military advantage to European powers that had stronger navies and did not need to rely on private vessels to achieve maritime military goals.
Although the United States did not renounce its legal right to engage in the practice, privateering largely faded as a strategic option in the late 19th century as a result of technological and policy developments,including a U.S. program to build a significantly larger and more advanced naval force. Developments in international practice and law also cast doubt on whether privateering remains compatible with international law. At the beginning of the 20th century, Congress removed the financial incentive for privateering by abolishing prize money in U.S. domestic law. Observers and Members of Congress haves sometimes called for revitalization of the practice by issuing letters of marque and reprisal designed to address contemporary problems, such as responding to international acts of aggression, apprehending terrorists overseas, combatting modern piracy, and responding to cyberattacks, but no legislation authorizing the instruments has been passed since the 1860s....
....MUCH MORE
Related, April 2020 - The U.S. Naval Institute Hus Ungated All Issues Of "Proceedings"
Also Naval History Magazine.
Here's an article from Proceedings Vol. 146/2/1,406, April 2020:
U.S. Privateering Is Legal
Issuing letters of marque presents international legal risks—some real, others imagined—but these are manageable. Further, since a conflict with China might, to paraphrase Dean Acheson, threaten the power, position, and even the existence of the United States, the demands of the conflict would limit the salience of law.1
...MUCH MORE
(See also: Unleash the Privateers!)
It's a fine line between being a privateer and a pirate, it pretty much depends on who catches you.
"There! That's what I think of ye. Before an hour's out, I'll stove in your old block house like a rum puncheon. Laugh, by thunder, laugh! Before an hour's out, ye'll laugh upon the other side. Them that die'll be the lucky ones..."
October 2020 - "Port Royal – The Sodom of the New World"
March 2022 - Yo Ho Ho, A Privateer's Life For Me: "Letters of Marque and Reprisal"
April 2022 - Even Privateers Need Insurance
