Rear Admirals Scott and Callaghan were both killed in action in the naval battle of Guadalcanal. Admiral Halsey, who received a promotion, asked that his stars be given to the widows of the two men because, he said, their actions earned him that promotion. Halsey could not have known it at the time, but Admiral Scott was killed in a friendly fire incident aboard the USS Atlanta when it was accidentally fired upon by the USS San Francisco.
In preparation for the role, James Cagney interviewed hundreds of men who had served with Adm. Halsey, and interviewed him twice. Cagney later called this role the most difficult of his career.
Admiral Halsey visited the set with his son, William F. Halsey III at Marine Corps Base Camp Pendleton, California. The young Halsey would later remark how much Cagney resembled his father.
The decision to intercept Yamamoto's plane was not Admiral Halsey's alone. The decision was made by Admiral Nimitz after consulting with Halsey.
Admiral Halsey did not live to see the release of this film, passing away on August 16, 1959, a couple months after production ended.