He did his duty. No finer military organization than the Marine Corps exists in the world. George Dewey. Admiral of the Navy. Will You? Join for active service land and sea. U.S. Marines. Apply at 24 East 23rd St., New York, N.Y., circa 1917-19. The United States Marine Corps (USMC) is a branch of the United States Armed Forces responsible for providing power projection from the sea, using the mobility of the United States Navy to rapidly deliver combined-arms task forces. During World War I veteran Marines served a central role in the late American entry into the conflict. The Marine Corps had a deep pool of officers and NCOs with battle experience, and experienced a small expansion. The Corps entered the war with 511 officers and 13,214 enlisted personnel, and by 11 November 1918 had reached a strength of 2,400 officers and 70,000 enlisted. George Dewey (December 26, 1837 - January 16, 1917) was an admiral of the United States Navy. He is best known for his victory at the Battle of Manila Bay during the Spanish-American War. He is also the only person in the history of the United States to have attained the rank of Admiral of the Navy, the most senior rank in the United States Navy. He died in 1917 at the age of 79. Undated, uncredited artist.