Leatherneck is a military slang term for a member of the United States Marine Corps, or of the Corps of Royal Marines. It is generally believed to originate in the wearing of a "leather stock" that went around the neck. Contrary to popular opinion, it was not used to protect the neck during swordfights. It was merely to keep the head and neck erect when wearing the uniform.
The term "leatherneck" was derived from a leather stock once worn around the neck by both American and British Marines and soldiers. Beginning in 1798 "one stock of black leather and clasp" was issued to each United States Marine every year. Its use as a synecdoche for Marines began as a term of ridicule by sailors.
The dress blue uniform of the US Marines still bears a tribute to that stock collar today, with a stiff cloth tab behind the front of its collar.
This stiff leather collar, fastened by two buckles at the back, measured between 2.5 and more than 3 inches tall in front, tapering toward the back. The origin of the leather neck collar, also known as a "stock", has to do with early 19th-century military fashion trends in Europe and North America; its use among enlisted men supposedly improved their military bearing and appearance by forcing the chin high and posture straight.
The stock was uncomfortable, but Marines would be punished for failure to wear them on duty, so some would have the stock stitched to their coats to ensure it was always on their uniform. General George F. Elliott, recalling its use after the American Civil War, said the "effect of the stock when buckled around a man's neck was to hold his head high in the air, like geese looking for rain".
The stock was dropped as an article of American Marine uniform in 1872, after surviving through the uniform changes of 1833, 1839, and 1859.
The stock collar was worn originally to protect the neck from sword cuts, such as cutlass slashes while boarding ships, and to maintain an erect posture. The leather stock was adopted three years prior to the Barbary War in which United States Marines first fought North African Islamic pirates armed with scimitars. This is disputed as leather is not considered adequate protection against a striking object. On Royal Naval vessels of the 18th & 19th Century, Royal Marines acted as the ship's guard. Additionally, as Marksmen firing from the rigging during sea engagements, shore detachments, landing parties, etc. Commanded by a Marine officer, and their own NCO's; these Men were a sub-group within the ship's company, and not part of the crew. This was a deliberate segregation, as Marines were responsible for safeguarding supplies, firearms, and Naval Officers from their crew. Most British sailors of the era were press-ganged into service, whereas a Marine enlisted. Trusted by the Navy command, disliked by the Sailors as the guardians of Authority. A thick, stiff leather collar provided protection for a Marine Sentry from having their throat cut by mutineers. Hence the derogatory term used by Sailors to describe a Marine: leatherneck.
While the American Marine Corps nickname "leatherneck" is generally attributed to the wear of the leather stock, some argue that the use of the term for British Royal Marines is not based on that garment, but instead on the tough and "leathery" nature of a weathered and unwashed neck, noting that "bootneck" is also a British slang term for a marine.
'Leatherneck,' ... denoted the U.S. Marine, whose 19th-century uniform had featured a high leather collar that sailors ridiculed.
This leather collar served to protect the neck against cutlass slashes and to hold the head erect in proper military bearing. Sailors serving aboard ship with Marines came to call them 'leathernecks.' Use of the leather stock was retained until after the Civil War when it was replaced by a strip of black glazed leather attached to the inside front of the dress uniform collar. The last vestiges of the leather stock can be seen in today’s modern dress uniform, which features a stiff cloth tab behind the front of the collar. The term 'leatherneck' transcended the actual use of the leather stock and became a common nickname for United States Marines.