After his service in World War I, Colonel Ellis served as an intelligence officer in the Dominican Republic from April to December 1920, followed by service as head of the intelligence section of the Division of Operations and Training with Headquarters Marine Corps from December 1920 to May 1921. His next assignment was as the FIRST SPY in the U.S. Marine Corps, when he took on clandestine reconnaissance missions in the Pacific to monitor Japanese military buildup there. He died under mysterious circumstances on the Japanese-held island of Palau in the Caroline Islands on May 12, 1923.




