Diamond was born May 30, 1890, at Bedford, Ohio. He enlisted at age 27, and though older than most recruits, the difference never was noticeable. Diamond enlisted in the Marine Corps at Detroit, Michigan, 25 July 1917, listing as his former occupation "railroad switchman."
Because of the incredible voice, which matched his 5-foot, 11-inch, 200-pound frame, Diamond was once dubbed "The Honker". Many of his comrades at Guadalcanal considered him "a human air-raid warning system."
World War I
As a corporal in January 1918, he shipped out from Philadelphia aboard the USS Von Steuben bound for Brest, France. He saw action with the famous 6th Marines in the battles at Chateau Thierry, Belleau Wood, the Aisne-Marne, St. Mihiel and the Meuse-Argonne. Promoted to the grade of sergeant, he marched to the Rhine with the Army of Occupation. At war's end, "Mr. Leatherneck" returned to America, and received an honorable discharge.
Railroading, and civilian life in general, did not suit him, and on 23 September 1921, Diamond re-enlisted.
World War II
Following the Japanese attack at Pearl Harbor, Diamond shipped out to Guadalcanal with Company H, 2nd Battalion, 5th Marines, 1st Marine Division, arriving at the beaches 7 August 1942. He was then 52 years old.
Though not a "spit-and-polish" Marine, Diamond prove himself an expert with both 60- and 81mm mortars, his accurate fire being credited as the turning point of many an engagement in the Pacific during World War II. Among the many fables concerning his Guadalcanal service is the tale that he lobbed a mortar shell down the smoke stack of an off-shore Japanese cruiser. It is considered a fact, however, that he drove the cruiser from the bay with his harassing "near-misses".
Diamond retired on 23 November 1945, and returned to his home in Toledo, Ohio. His death at the Great Lakes, Illinois, Naval Training Center Hospital, September 20, 1951, was followed by a funeral, with full military honors, at Sylvania, Ohio.