Jack served as president of The Summit Foundation for 28 years. He served as a trustee with many other local nonprofit organizations, including Overlook Hospital Foundation, SAGE Eldercare, Northern New Jersey Estate Planning Council, Summit Area United Way, Summit Volunteer First Aid Squad, Summit Family Service Association, Summit Speech School and Oak Knoll School of the Holy Child. Cooper was a partner at Lindabury, McCormick, Estabrook and Cooper, P.C.