In 1863, Adm. David Dixon Porter famously wrote, "A ship without Marines is like a garment without buttons." Remembering that this was a time before t-shirts when people dressed properly, his words hold true. Sailors crew and fight a ship, but a Marine detachment is a critical element on a warship. Also Read: The role of the Marine Corps during the Civil War The Army loves to remind the Marine Corps that the largest amphibious invasion in military history was conducted by soldiers.