United States Marine Corps

• 1. Introduction

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  The United States Marine Corps was born on the 10th of November 1775, when the Second Continental Congress resolved to raise two battalions of marines in Philadelphia. Captain Samuel Nicholas, nominated for the task by John Adams, had one battalion of 300 men recruited within weeks. What followed was a fighting force whose history would stretch from a British ammunition depot in the Bahamas to the volcanic sands of Iwo Jima, from the halls of Chapultepec to the streets of Fallujah. How did an infantry unit originally designed to fight aboard wooden sailing ships become one of the most versatile military organizations on earth? The answer lies in a sequence of reinventions, each one driven by the pressures of a changing world and the stubborn identity of an institution that has never been entirely comfortable with anyone else's definition of its purpose.

• 2. Born at Sea

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  America's first amphibious assault took place on the 3rd of March 1776, when Continental Marines came ashore at New Providence in the Bahamas and seized Fort Montagu and Fort Nassau, a British ammunition depot and naval port. Their original purpose was bound to the ship itself. Marines secured vessels against mutiny, guarded officers, crewed raiding parties, and served as marksmen during boarding actions. Their berthing was often placed deliberately between officers' quarters and the rest of the crew.

  The institution was disbanded at the end of the Revolutionary War in April 1783 and resurrected on the 11th of July 1798 as Congress prepared for the Quasi-War with France. Marines had already been enlisted as early as August 1797 for service aboard newly built frigates. The Corps's most celebrated early action came during the First Barbary War of 1801-1805, when William Eaton and First Lieutenant Presley O'Bannon led eight marines and five hundred mercenaries in an effort to capture Tripoli. They reached only Derna, but the campaign was immortalized in the Marines' Hymn and in the Mameluke sword that Marine officers carry to this day.

  By the time the original naval role began to fade with the professionalization of the naval service, the Corps had already developed a secondary identity ashore. The Advanced Base Doctrine of the early 20th century codified combat duties on land, and the USMC Sea School, a remnant of the ship-focused era, closed in 1987. The last marine detachments aboard ships were disbanded in 1998.

• 3. The Commandant Who Saved the Corps

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  After the War of 1812, the Marine Corps drifted into what one might fairly call institutional stagnation, a malaise that ended with the appointment of Archibald Henderson as its fifth commandant in 1820. Henderson turned the Corps outward, dispatching it on expeditionary duties in the Caribbean, the Gulf of Mexico, Key West, West Africa, the Falkland Islands, and Sumatra. When President Andrew Jackson attempted to merge the Marine Corps with the Army, it was Henderson who thwarted him.

  Congress responded by passing the Act for the Better Organization of the Marine Corps in 1834, which placed the Corps formally under the Department of the Navy as a sister service. Henderson then volunteered the Marines for the Seminole Wars of 1835 and personally led nearly half of the entire Corps, two full battalions, into that conflict.

  A decade later, in the Mexican-American War of 1846-1848, Marines took part in the assault on Chapultepec Palace in Mexico City, an action celebrated in the Marines' Hymn as the "Halls of Montezuma". The final assault was led by Army General Winfield Scott, who organized two storming parties of roughly 250 men each, about 40 of whom were marines. The broader Corps identity was already pulling away from its naval origins and toward an expeditionary function that would define it for the next two centuries.

• 4. From Belleau Wood to Iwo Jima

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  When the United States entered the First World War on the 6th of April 1917, the Marine Corps had 511 officers and 13,214 enlisted personnel. By the 11th of November 1918, it had grown to 2,400 officers and 70,000 enlisted. Opha May Johnson, born in 1878, became the first woman to enlist when she joined the Marine Corps Reserve in 1918. By the end of the war, 305 women had served.

  At the Battle of Belleau Wood that same year, Marine Corps lore holds that German soldiers nicknamed the Marines Teufel Hunden, meaning Devil Dogs, for their reputation as shock troops and marksmen at ranges up to 900 meters. The Corps' own History Division notes the nickname predated Belleau Wood in print by six weeks and was likely coined by an American war correspondent.

  Between the wars, the Corps studied and refined the doctrine of amphibious assault on defended coastlines. Lieutenant Colonel Earl Hancock "Pete" Ellis was among the officers who foresaw a Pacific war with Japan and prepared accordingly. Two slim manuals published in the 1930s, the Small Wars Manual and the Tentative Landing Operations Manual, established the doctrinal foundations for both counterinsurgency and large-scale amphibious operations. When World War II arrived, those foundations held.

  The Battle of Iwo Jima, which began on the 19th of February 1945, stands as arguably the most famous Marine engagement of the war. The Japanese had prepared the island with pillboxes and a network of tunnels. American forces reached the summit of Mount Suribachi on the 23rd of February. The battle produced 26,000 American casualties and 22,000 Japanese. By the war's end, some 600,000 Americans had served in the Corps, nearly 87,000 had become casualties, and 82 had received the Medal of Honor.

• 5. An Institution Under Threat

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  Secretary of the Navy James Forrestal had predicted at Iwo Jima that the Marine flag raising meant "a Marine Corps for the next five hundred years". But the postwar period brought a budget shock and an Army-led effort to absorb Marine assets into the other services. The Corps drew on congressional support and on what became known as the "Revolt of the Admirals" to resist dismemberment, securing statutory protection in the National Security Act of 1947.

  The political friction was not entirely new. In 1950, President Harry Truman wrote in a letter to Representative Gordon L. McDonough, dated the 29th of August, that "The Marine Corps is the Navy's police force and as long as I am President that is what it will remain. They have a propaganda machine that is almost equal to Stalin's." McDonough read the letter into the Congressional Record. The backlash was swift. Truman apologized to the Marine commandant, writing that he "sincerely regretted the unfortunate choice of language," though he did not alter his view that the Corps should remain under the Navy secretary. He made amends by showing up unannounced at the Marine Corps League, where he was given a standing ovation after saying, "When I make a mistake, I try to correct it."

  In 1952, the Douglas-Mansfield Act gave the commandant an equal voice with the Joint Chiefs of Staff on matters affecting Marines and enshrined the structure of three active divisions and air wings that still exists today.

• 6. Every Marine a Rifleman

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  The doctrine that distinguishes the Corps from other Western militaries is encapsulated in a single phrase attributed to Commandant Alfred M. Gray, Jr.: "Every Marine is a rifleman". All marines, regardless of specialization, complete infantry training. All officers complete additional training as infantry platoon commanders. The principle was tested visibly at the Battle of Wake Island during World War II, when Marine aircraft were destroyed and pilots took up positions as ground officers, leading supply clerks and cooks in a final defensive effort.

  The basic deployed unit is the Marine Air-Ground Task Force, or MAGTF, which integrates a ground combat element, an aviation combat element, and a logistics combat element under a single command. This structure gives the Corps a self-sufficient combined-arms capability that does not depend on inter-service coordination for basic function. A MAGTF can deploy almost anywhere in the world within days.

  Marine aviation has consistently rejected theories that strategic bombing alone can win wars. Instead, Marine air has focused on close air support for infantry. The Corps operates 313 V-22 Ospreys, 183 F-35B Lightning IIs, and 78 AV-8B Harrier IIs, with many fighter attack squadrons embedded directly in Navy carrier air wings. In 2020, the Corps retired its M1A1 Abrams tanks entirely, with General David Berger describing them as "operationally unsuitable for our highest-priority challenges," making the Army the sole American operator of tanks.

• 7. Culture and Identity

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  John Philip Sousa enlisted as a Marine apprentice at age 13 and served from 1867 until 1872, then returned from 1880 to 1892 as the leader of the Marine Band, which John Adams dubbed the "President's Own". The Marines' Hymn is the oldest official song in the United States armed forces. The motto Semper Fidelis, meaning Always Faithful, was adopted around 1883, and the Eagle, Globe, and Anchor emblem was adopted on the 19th of November 1868.

  The Corps celebrates its birthday on the 10th of November each year in a cake-cutting ceremony where the first slice goes to the oldest Marine present, who then passes it to the youngest. Close Order Drill is central to training from the earliest weeks of boot camp onward, used to instill precision and automatic response to command.

  Marine recruit training is the longest among all American military services at 13 weeks. In 2001, the Corps introduced the Marine Corps Martial Arts Program, which blends Taekwondo, Karate, Jujitsu, Brazilian jiu-jitsu, Eskrima, and Muay Thai. The program uses a five-belt system running from tan to black and begins in boot camp.

  On the question of identity after service, the Corps encourages the idea that the title is permanent. The phrase "Once a Marine, always a Marine" reflects a deliberate institutional stance; many veterans reject the term "ex-Marine" outright. As of December 2024, the Corps counts around 169,000 active duty members and some 33,000 in reserve, a far cry from the 300 men Captain Samuel Nicholas raised in Philadelphia in late 1775, though the insistence on that founding date has never wavered.