A Brief History of the 9th Marines is revised at this time in order to provide a concise narrative of the activity of the regiment since its activation in 1917 to its present participation in Vietnam as part of the III Marine Amphibious Force. This history is based on the official records of the United States Marine Corps and appropriate secondary sources. It is published for the information of those interested in the regiment and the role it played and continues to play in adding to Marine Corps traditions and battle honors.