John Callahan, a longtime East Chop summer resident, died at home in New London, N.H. on May 23.

Born in Philadelphia in 1933 and raised in Westfield, N.J., he was an alumnus of Dartmouth College and of the Yale School of Drama. Following service as a reserve officer in the U.S. Army, he embarked on a career in college, university and museum administration and eventually served in senior positions with the University of Chicago, Amherst College, Winterthur Museum and the American Philosophical Society.

In parallel with these assignments Mr. Callahan established a diverse consulting practice dedicated to the development of sound organization, management and communications strategies for charitably supported institutions. He consulted pro bono for the Martha’s Vineyard Museum. Other clients over the years included the Marine Biological Laboratory in Woods Hole, the American Association for the Advancement of Science, the Aspen Institute, the Independence National Park Institute, the Library of Congress, the Monell Chemical Senses Center, the University of the Arts, the Glaucoma Service Foundation of Wills Eye Hospital and the Woodrow Wilson National Fellowship Foundation.

Mr. Callahan considered himself fortunate to have served on the boards of a number of charitably supported institutions including the Council for the Advancement and Support of Education, the Hawk Mountain Sanctuary Association, the Fund for Arts and Culture, the Acting Company, the Common School, the National Building Museum, the Delaware Theatre Company and Kimball Union Academy. Colleagues often described him as one of his generation’s most talented and capable people in institutional advancement and administration; he committed himself to every assignment with a sense of urgency, an aspiration of perfection and a fundamental integrity that is rare even at the best institutions.

In 1958 Mr. Callahan married Virginia Clark, his high school sweetheart, in the Thorndike-Hilton Chapel on the campus of the University of Chicago. She survives him, as do a son, Clark R. Callahan of Norwich, Vt., and a daughter, Laura B. Callahan of Sydney, Australia, along with four granddaughters, Kelsey and Nina of Sydney and Katherine and Claire of Norwich.

Describing himself as an ardent if not notably accomplished writer, Mr. Callahan created over the years an extensive body of written work including several volumes of poetry, 15 short stories, a dozen stories for children, a series of vignettes and 10 full-length plays. “Writing,” he observed at one point, “is a toilsome and frustrating exercise, but not writing is a substantially more difficult problem to deal with.”

Services will be private.

Chadwicks of New London is assisting with arrangements.