Nearly five years ago, Charles F. Feeney sat in a cushy armchair in an apartment on the east side of Manhattan, grandchildren's artwork taped to the walls, and said that by the end of 2016, he was going to hand out the last of a great fortune that he had made. It was a race: Mr. Feeney was then 81, and Atlantic Philanthropies, a collection of private foundations he had started and funded, still had about $1.5 billion left. Writing checks willy-nilly was not Mr. Feeney's way. Last month, Mr. Feeney and Atlantic completed the sprint and made a final grant, $7 million to Cornell University, to support students doing community service work. He had officially emptied his pockets, meeting his aspiration of "giving while living." Altogether, he had contributed $8 billion to his philanthropies, which have supported higher education, public health, human rights and scientific research. None of the major American philanthropists have given away a greater proportion of their wealth, and starting in 1982, Mr. Feeney did most of this in complete secrecy, leading Forbes magazine to call him the "James Bond of philanthropy." For years, Atlantic's support came with a requirement that the beneficiaries not publicize its involvement. Beyond Mr. Feeney's reticence about blowing his own horn, "it was also a way to leverage more donations - some other individual might contribute to get the naming rights," said Christopher G. Oechsli, the president and chief executive officer of Atlantic.