"John is an incredible example for each of us. He loved people and our community," said William J. McCarthy, executive director of Catholic Charities of Baltimore.
"He deeply cared for people in need and had a passionate interest in and supported organizations that helped the poor, the marginalized and those in need of medical care," said Mr. McCarthy. "John was a champion of good works. He constantly brought others to understand the needs of people and organizations that improved lives."
Rebecca Rothey, director of major and planned giving at the Baltimore Community Foundation, called Mr. Gardner "humble and reserved. He was the exemplar of the greatest generation who served his country, family and community.
"He was understated but lived by those profound principles. Some people you are privileged to know, and John was one of them," said Ms. Rothey.
The son of a Ford salesman and a homemaker, John Wilson Gardner was born in Baltimore and raised in the city's Ashburton neighborhood.
In 1934, Mr. Gardner became a boarding student at McDonogh School, where he lived year-round on its Owings Mills campus studying and working on its farm.
After graduating from McDonogh in 1938, he began studying accounting at the University of Baltimore, which was interrupted by World War II.
Mr. Gardner enlisted in the U.S. Naval Air Corps in 1942 and was trained as a pilot to fly Grumman F4F Wildcats and F6F Hellcats, both of which were carrier-based fighter planes.
Assigned to the carrier USS Princeton in the Pacific Theater, in 1944 Mr. Gardner was called back, to the mainland where he was assigned to a naval air station in the South. There he was a flight instructor on SNB Twin Beech aircraft, planes that were used to instruct pilots, navigators, gunners and bombardiers.
During the Battle of Leyte Gulf, east of Luzon on Oct. 24, 1944, the Princeton was attacked by a single Japanese dive bomber and later sank.
"He said it was a single plane with a single bomb that sunk the Princeton and that he had been very lucky when he had been called back to the U.S. to teach," said Frank G. Lidinsky, a longtime friend and attorney.
"After the close of World War II, he was approached by World War I flying ace Eddie Rickenbacker, requesting him to be a pilot and instructor for his commercial air enterprise, Eastern Air Lines," said Mr. Lidinsky. "John declined because he wanted to return to Baltimore to take care of his disabled father."
Mr. Gardner earned a bachelor's degree in 1949 from what is now Loyola University Maryland. In the early 1950s, he began working in sales and later became an accountant for Davidson Transfer & Storage. He retired in the 1990s.
In 1951, he married Jane Baines, and the couple lived in the Loch Raven-Towson area. His wife died in 1988, and since 1997 he had lived at the Parkville retirement community.
"John was a very kind and generous man," said Mr. Lidinsky. "He established a number of charitable gift annuities during his lifetime with various institutions and benevolent associations."
The beneficiaries of Mr. Gardner's philanthropy, Mr. Lidinsky said, included the University of Maryland St. Joseph Medical Center, Jesuits Seminary Guild, McDonogh School, Catholic Charities, American Cancer Society and the American Heart Association.
"In his philanthropy, he gave back to a school that made a huge difference in his life, a hospital that kept him alive, and he wanted to take care of the less fortunate," said Ms. Rothey.
"John had never forgotten that McDonogh had made it possible for him to attend the school because it had given him a scholarship back in the '30s," said Mr. Lidinsky.
"He never forgot that," said Kristen S. Kinkopf, who is director of mission integration and planning at Catholic Charities. "He exuded humility and gratitude and felt the obligation to give back."