William E. Macaulay, a billionaire energy investor whose record $30 million gift to the City University of New York has given thousands of select students the same opportunity he was accorded a half-century ago as a middle-class teenager from the Bronx — to graduate tuition free from an elite college — died on Nov. 26 at a hospital in Cleveland. He was 74.

The cause was a heart attack, his daughter Elizabeth Macaulay-Lewis said.

Mr. Macaulay made his fortune in energy company buyouts, overseeing the transformation of the First Reserve Corporation, which he acquired in 1983, into one of the field’s largest private-equity firms. He was chief executive until 2015, shared the title until 2017, and had been executive chairman since then.

He and his wife, Linda, also contributed to the American Museum of Natural History (she was a co-chairwoman of the board); the Rogosin Institute, a kidney treatment and research center, at NewYork-Presbyterian Hospital and Weill Cornell Medical College; and the Macaulay Library at the Cornell University Laboratory of Ornithology. (The couple were avid bird watchers, logging 6,625 species in 147 countries.)

Mr. Macaulay especially prided himself on what may be his most enduring legacy: the highly selective college, founded in 1999, at which the most promising students from eight of the City University’s senior campuses receive additional academic mentoring and financial support.