United States Marine Corps A decade later, in the Mexican–American War (1846–1848), the Marines made their famed assault on Chapultepec Palace in Mexico City, which would be later celebrated as the "Halls of Montezuma" in the Marines' hymn. In the 1850s, the Marines would see further service in Panama and Asia, attached to Matthew Perry's East India Squadron on its historic trip to the Far East. The Marine Corps played a small role in the Civil War (1861–1865); their most prominent task was blockade duty. As more and more states seceded from the Union, about a third of the Corps' officers left the United
Organization of the United States Marine Corps Navy. Both the Chief of Naval Operations (CNO) and Commandant of the Marine Corps (CMC), heads of their respective services, report directly to the Secretary of the Navy (SECNAV). As a result, the Navy and Marine Corps have a close relationship, more so than with other branches of the United States Armed Forces. Recent whitepapers and promotional literature have commonly used the phrase "Navy-Marine Corps Team" . This relationship stems from the Navy providing transport, logistical, medical, and religious service as well as combat support to put Marine units into the fight where they are needed. Conversely, Marines are responsible