United States Marine Corps served as a convenient resource for interventions and landings to protect American interests overseas. The Corps was involved in over 28 separate interventions in the 30 years from the end of the American Civil War to the end of 19th century. They would be called upon to stem political and labor unrest within the United States. Under Commandant Jacob Zeilin's tenure, Marine customs and traditions took shape: the Corps adopted the Marine Corps emblem on 19 November 1868. It was during this time that "The Marines' Hymn" was first heard. Around 1883, the Marines adopted their current motto ""Semper Fidelis""
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,