Mrs. Madeira was as devoted to the museum as her family had been. She provided funding for musical programs, exhibitions, and conservation of works of art, and endowed curatorial positions and educational programs.
In 2013, Mrs. Madeira endowed the position of associate curator of decorative arts, which had been developed and held for many years by her husband, Louis C. Madeira IV, an expert on early American silver, furniture, and porcelain made in Philadelphia.
She also donated important works of art to the museum, her family said in a statement released by the Philadelphia law firm Ballard Spahr L.L.P..
Joseph Rishel, the museum's Gisela and Dennis Alter senior curator of European painting before 1900, said: "She was one of our greatest friends. Patsy was deeply interested in all that we did, especially in our efforts to continue to develop our collection, and took great pleasure in sharing with others the things that delighted her most."
In addition, Mrs. Madeira gave generously to charitable institutions in the Philadelphia area and Maine, especially those involved with the arts, medical research, and health care.
Mrs. Madeira graduated from Miss Porter's School in Farmington, Conn., in 1934. She maintained a house in Southwest Harbor, Maine, and spent summers there for many years.
From her early days, Mrs. Madeira was deeply engaged in a broad spectrum of activities, including studying music, appreciating and collecting art, horseback riding, playing bridge, and travel.
Mostly, though, she enjoyed engaging people in conversation with sensitivity and good humor.
"Not even at the very end did she ever lose her bountiful interest in people and all human pursuits," her family said in the statement. "She exhibited these traits at her 98th birthday party in May, demonstrating the vigor and mental acuity of a much younger person."
Mrs. Madeira's husband of 55 years died in 1993 at age 77.
Surviving are a daughter, Alexandra M. Harrison; a son, C. Tyson; three grandchildren; and three great-grandchildren.
Services and burial were Wednesday, Aug. 13.
Donations may be made to the Philadelphia Museum of Art - Annual Fund, P.O. Box 7646, Philadelphia, Pa. 19101.