Dr. Hennessey earned a medical degree in 1963 from the Temple University School of Medicine before joining the Air Force as a physician in Orlando, Fla. After his discharge in 1967, he studied pediatrics at St. Christopher's Hospital for Children in Philadelphia.
Over the next 39 years, he served as a staff pediatrician at St. Christopher's, as well as at Holy Redeemer and Nazareth Hospitals.
Until retiring in 2006, he also maintained a private practice in office space over the family garage in Huntingdon Valley.
His daughter Kristen Clarke said he chose pediatrics because he simply loved children. They returned his sentiment.
"I used to work in his office," she said. "He'd have kids aged 18 or 19 still coming in to see him. 'Will the doctor still see us?' they asked. And he would."
The Hennesseys lived in Huntingdon Valley from 1967 to 2011, when Dr. Hennessey moved to the Scranton area to be near his daughters as his health failed.
In better times, Dr. Hennessey enjoyed boating on the Chesapeake Bay and Lake Ariel in Wayne County, Pa., where the family had a summer home.
He was a member of the Irish American Pediatric Society and liked to travel with society members to places such as Ireland and Canada.
He was married for 52 years to the former Marie Harding. They lived on the same block in Scranton.
Surviving, in addition to his wife and daughter, are sons Joseph and Patrick; daughters Bridget Weir, Elizabeth, Erin Butler, and Meghan Farrell; 16 grandchildren; five great-grandchildren; and nieces and nephews. A granddaughter, Caitlin, died in a car accident at age 22.
A Funeral Mass will be said at 10:30 a.m. Tuesday, April 30, at St. Albert the Great Roman Catholic Church, 212 Welsh Rd., Huntingdon Valley. Friends may call starting at 9:30 a.m. Interment will be in Resurrection Cemetery, Bensalem.
Condolences to the family may be offered at www.odonnellfuneral.com.
Contact Bonnie L. Cook at 215-854-2611 or firstname.lastname@example.org.