Complex sentence: During June 1938, Hudson attended Gunnery School aboard the cruiser "USS Minneapolis" and after the finishing of the course in August of that year, he was appointed Commanding Officer of the Marine Detachment aboard the cruiser "USS Quincy".
Split into simpler sentences: During June 1938, Hudson attended Gunnery School aboard the cruiser "USS Minneapolis" and after the completion? Of the course in August of that year, he was appointed Commanding Officer of the Marine Detachment aboard the cruiser "USS Quincy".