Mr. Maddux, center, with, from left , son Fielding L. Maddux, wife Yoli Maddux, daughter Katharine Maddux and son H. Cabell Maddux III. (Family Photo)

H. Cabell Maddux Jr. and his wife were traveling in Europe in 1971 when they learned that their 26-year-old daughter, Katharine, had been fatally shot at the cottage where she lived on their family’s estate in McLean, Va.

Katharine’s estranged husband, Alfred B. Houghton, a lawyer who was described in news accounts as an alcoholic, later admitted he killed her and pleaded guilty to second-degree murder.

Despite their grief, Cabell and Yoli Maddux set out immediately to memorialize their daughter’s life, and particularly her interest in children. Within days of her death, they formed the philanthropic organization that became the Katharine Pollard Maddux Memorial Mental Health Foundation.

In the past four decades, the foundation has given nearly $5 million in grants to programs benefiting underserved children in the Washington area, administrator Stephanie deSibour said.

Mr. Maddux, 97, died April 15 at his home in McLean. The cause was congestive heart failure, said his son H. Cabell Maddux III.

Henry Cabell Maddux Jr. was born July 6, 1916, in San Francisco. He was a 1935 graduate of Episcopal High School in Alexandria, Va., and received a bachelor’s degree in English from the University of Virginia in 1939. During World War II, he served in the Navy, including in the Allied invasions of Africa and Italy.

Mr. Maddux followed his father into the hospitality business and co-owned hotels in Washington, Cape May, N.J., and Lake Worth, Fla., before retiring in the early 1980s, his son said. Along with his wife, a daughter of former Panamanian president Ricardo J. Alfaro, he appeared at times in the newspaper society pages.

Mr. Maddux’s son said the foundation was started spontaneously after Katharine’s death when friends sent donations for the Maddux family to distribute in her honor. Among the first beneficiaries was an early-intervention program at the private Country Day School in McLean, where Katharine worked. The foundation also supported the Family Place in the District, which provides low-
income communities with parenting, educational and other services. Ann Barnet, a retired pediatric neurologist and a founder of Family Place, said the Madduxes “took a terrible tragedy and turned it into something good.”

The foundation also funded programs at the Ivymount School in Rockville, Md., which serves students with special needs and is now home to the Maddux School.

“Tens of thousands of children and families have been helped by this foundation,” said deSibour, a childhood friend of Katharine’s who is the assistant director of Ivymount.

Mr. Maddux’s wife died in 2005, after 64 years of marriage. Their son Fielding L. Maddux died in 1999. Survivors include a son, H. Cabell Maddux III of Warrenton, Va.; four grandsons; and 10 great-grandchildren.

Mr. Maddux and his wife frequently visited the sites of the programs they supported and schooled themselves in early-childhood development. They took on the passion of their daughter, deSibour said, and “went with that as their mission, probably never expecting that it would take off as it did.”

DeSibour said that during their visits, Mr. Maddux and his wife would sometimes watch the ongoing work with the children and remark on how much their daughter would have loved to see it.