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""
Assistant Commandant of the Marine Corps the Navy – may delegate to or prescribe for him. Orders issued by the Assistant Commandant in performing such duties have the same effect as those issued by the Commandant. When there is a vacancy in the office of Commandant of the Marine Corps, or during the absence or disability of the Commandant, the Assistant Commandant shall perform the duties of the Commandant until a successor is appointed or the absence or disability ceases. ! # ! class="unsortable"|Photo ! Rank ! Name ! Tenure from ! Tenure to ! Became Commandant Assistant Commandant of the Marine Corps The Assistant Commandant