Known for his work as a marine and naval engineer, he established the John J. McMullen & Associates architecture and engineering firm in New York City. He also owned the Norton Lilly shipping company and purchased both the Houston Astros and New Jersey Devils teams.
Following his graduation from the United States Naval Academy and his subsequent decade-and-a-half of military service, he earned advanced engineering and architecture degrees from the Massachusetts and Swiss Federal Institutes of Technology.
The United States Naval Academy's ice hockey arena was named in his honor.
His marriage to Jacqueline Everhart produced two sons and one daughter.
He owned a small portion of the New York Yankees baseball team; the team's primary owner was George Steinbrenner.