Donald M. Weller was born on May 1, 1908, in
Hartford, Connecticut, as the son of a
Methodist clergyman. He attended a grade school in
East Greenwich, Rhode Island, and later high school in
Pittsburgh, Pennsylvania. Following his graduation, he spent a year at
Carnegie Tech, before he received appointment to the
United States Naval Academy at
Annapolis, Maryland, in June 1926. As a
midshipman, he was an avid swimmer and saved the life of classmate in a boating accident in a stormy sea. In his final year at the academy, Weller shared a room with future
Commandant of the Marine Corps,
Wallace M. Greene. Following his return from the exercise, Weller served for some time as Detachment Officer at Marine Barracks within
Norfolk Navy Yard, before rejoined his 1st Battalion in January 1935. He was also promoted to the rank of first lieutenant during the same time. A major breakthrough in his career occurred when he was sent to the
Army Field Artillery School at
Fort Sill,
Oklahoma. Weller studied the application of
Naval gunfire support during the amphibious assault through study of the
Gallipoli Campaign while he prepared a term paper on the subject. He finished the Artillery School in July 1935 and returned to Battery "E" as an
executive officer. He continuously served with 10th Marines until June 1937, when he was appointed commander of the Marine detachment aboard the heavy cruiser
USS Tuscaloosa. For his new task, he was also promoted to the rank of captain in August 1937. During his service on Tuscaloosa, he simultaneously served as Control Officer of the
5"/25 caliber Anti-aircraft battery and used this opportunity to improve his knowledge of use of naval gun for support of the
landing operations. ==World War II==