Caleb Cresson “Cress” Wistar, 93, a retired procurement specialist for the Unisys corporation, died April 2, at The Hill at Whitemarsh.

During his tenure at Unysys, Mr. Wistar had served for a year at the $142 million Cheyenne Mountain complex, a military installation and nuclear bunker in Colorado Springs, Colo. In that capacity, he supported the Air Force and other government agencies in deploying the then-new NORAD system, which monitored U.S. and Canadian air space for missiles, space systems, and foreign aircraft through an early-warning system developed by the Burroughs Corporation before it became Unysys.

Retiring from Unysys in 1986, he continued his services to the Episcopal Church, especially at the Church of the Messiah in Lower Gwynedd, where he served as Rector’s Warden.

Born in Chestnut Hill and raised in Chestnut Hill, Trenton, N.J., Wyncote and Blue Bell, Mr. Wistar was a graduate of St. George’s School in Middletown, R.I.

After graduating from the University of Pennsylvania in 1943, he joined the Army Medical Corps as a corporal and served during World War II in Europe, where he supported the 101st Airborne Division and the 10th Armored Division in Bastogne during the Battle of the Bulge. He served in the Army Reserve, retiring as a major.

He enjoyed tending his small Blue Bell farm with its gardens, fields and assorted pets and animals.

He is survived by sons Stephen M. Wistar, of Phoenix, Ariz., Caleb C. Wistar IV, of Delmar, N.Y., Gilbert M. Wistar, of Portland, Ore., and James B. Wistar, of Philadelphia; a daughter, Alisa W. Johnson, of Huntingtown, Md.; his companion, Caroline Wistar, and 10 grandchildren. Mr. Wistar’s wife, Alisa, died in 2007.

A memorial service was held May 9 at the Church of the Messiah, 1001 DeKalb Pike, Lower Gwynedd, PA 19002. Memorial donations may be sent to the above church or to the Wistar Institute, 3601 Spruce St., Philadelphia, PA 19104. – WF