When was the last letter of marque issued in America

1. Executive summary

The last time the United States actually issued letters of marque was in the early nineteenth century, tied to the War of 1812 and immediate postwar actions; Congress also authorized commissions in 1815 against the Dey of Algiers (the Second Barbary War), and later permitted—but did not see the use of—similar authority during the Civil War (President Lincoln never exercised it) ^{[1] [2]}. Persistent myths that a U.S. letter of marque was issued in World War II (for example to a Goodyear blimp in 1942) have been discredited in detailed modern scholarship ^[3].

2. The Constitutional power and early practice

The Constitution gives Congress the exclusive power to grant letters of marque and reprisal, a practice rooted in Revolutionary-era privateering that states and the Continental Congress used in the 1770s and 1780s ^{[2] [4]}. Congress regularly authorized privateering during early conflicts—most notably in the Quasi-War with France and again during the War of 1812—when the legislature authorized the President to issue letters and set statutory conditions for their use ^[1].

3. The War of 1812 and the immediate aftermath

Privateering reached its apogee in the War of 1812, when Congress explicitly empowered the President to grant commissions and Congress passed statutes detailing their terms eight days after the declaration of war; this era is widely cited as the last period in which Congress actively issued letters of marque in significant numbers ^[1]. Congress again authorized commissions in 1815 against the Dey of Algiers to protect American commerce in the Mediterranean—often treated as the tail end of statutory issuance in that early-nineteenth-century era ^[1].

4. Civil War authorization that was never used

Congress’s final formal authorization to allow privateering in the nineteenth century came when it gave the President authority to issue letters of marque during the Civil War, but President Abraham Lincoln never exercised that power—meaning no new presidential-issued letters flowed from that authorization ^[1]. Scholarly accounts and the Congressional Research Service emphasize that after the Civil War the U.S. as policy avoided privateering and has not authorized a President to issue such instruments since that conflict ^{[2] [5]}.

5. International law, the Paris Declaration, and the post‑1856 consensus

Although the United States never formally acceded to the 1856 Declaration of Paris which largely outlawed privateering, subsequent American policy and practice moved away from commissioning private actors to wage naval war; reference works note that the U.S. has issued no letters of marque since the mid‑nineteenth century and that the practice fell into disfavor internationally ^{[6] [7]}.

6. The World War II legend and modern corrections

A persistent popular story claims a U.S. letter of marque was issued in 1942 to a Goodyear blimp to hunt Japanese submarines; careful modern legal and historical scholarship calls this a journalistic legend without documentary support—there were no World War II letters of marque, and the tale appears to have grown from wartime confusion about civilian participation in coastal patrols ^[3]. Contemporary legal references reiterate that while the constitutional power remains, the United States has not actually issued letters of marque in modern times ^[8].

7. Bottom line, ambiguity, and limits of the record

The safest, evidence-based conclusion is that the last genuine issuances occurred in the early 1800s—centered on the War of 1812 and the 1815 Algerine commissions—with Congress later authorizing but not effectuating new letters during the Civil War; claims of later issuances (notably 1942) lack documentary backing and have been debunked in scholarship ^{[1] [2] [3]}. This assessment relies on the Congressional Research Service, legal reference works, and academic debunking; if there are obscure or unilateral municipal or corporate documents purporting to be “letters” after the Civil War, those are not supported as lawful U.S. letters of marque in the sources reviewed ^{[1] [8] [3]}.