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
Commandant of the Marine Corps "subject to the authority, direction, and control of the Secretary of the Navy." As stated in the U.S. Code, the Commandant "shall preside over the Headquarters, Marine Corps, transmit the plans and recommendations of the Headquarters, Marine Corps, to the Secretary and advise the Secretary with regard to such plans and recommendations, after approval of the plans or recommendations of the Headquarters, Marine Corps, by the Secretary, act as the agent of the Secretary in carrying them into effect, exercise supervision, consistent with the authority assigned to commanders of unified or specified combatant commands under chapter 6 of this title,