Mr. Pollin, a builder by trade, was a presence in the Washington area for his housing construction and charitable work. He financed medical research, aided the poor and helped feed children in developing countries through Unicef. Abraham Pollin was born on Dec. 3, 1923, in Philadelphia. When he was 8 his family moved to Washington, where his father, Morris, became a plumbing and heating contractor. After graduating from George Washington University in 1945, Mr. Pollin worked for his father, then opened a construction company. Mr. Pollin joined with two partners in buying the Bullets in 1964, and he gained full ownership four years later. The Bullets made the N.B.A. finals in 1971 behind the future Hall of Fame guard Earl Monroe, but were swept by the Milwaukee Bucks. After Mr. Pollin moved the Bullets to Washington’s Maryland suburbs in 1973, when he built the Capital Centre, later known as US Airways Arena, they continued to thrive. They went to the finals again in 1975, when they were swept by the Golden State Warriors, and then defeated the Seattle SuperSonics in a seven-game championship series in 1978. Mr. Pollin’s charitable endeavors reached from Washington to developing countries. Locally, he financed college educations for needy students through his I Have a Dream Foundation and provided meals for the homeless in the Abe’s Table program. He raised money for the Kennedy Center, the Salvation Army and the United Jewish Appeal. Mr. Pollin and his wife created the Linda and Kenneth Pollin Foundation at Harvard Medical School and financed pediatric medical research in New York. They also established a $1 million research fund at the Society for Progressive Supranuclear Palsy.