Copy editor and actor India Cooper died on May 17 in Madison, Ind., after a brief illness. She was 67.

After working as an actress and director in Chicago, Cooper moved to New York City in 1990 and was hired as a freelance copy editor at Oxford University Press, and over the 30 she worked as a copy editor for Oxford, Chicago University Press, Macmillan, and other publishing houses.

Cooper edited many prize-winning books, among them four Pulitzer Prize winners for Oxford University Press. Her contributions to these books were substantial, and for all of them she was highly regarded by editors and authors for her amazing, thorough work. She was also commended for her ability to bring out excellence in others. One managing editor said that “once India copyedited an author’s book, she was requested by that author for every following book. I have never heard one complaint about her, not even the tiniest objection to anything she did or queried.”

A few years ago, Cooper explained why she loved being a copy editor for a publishing panel:

“Though I almost never get to meet our authors in person, I think back happily on moments of delight with each one—cracking jokes back and forth within the margins, each in our different colored pencil; me leaping up wherever I was to run and read a paragraph to whomever I could find, ‘Listen to this, I had no idea,’ ‘Listen to this, it’s beautiful,’ ‘Listen to this, it’s so sad’—and perhaps less happy but just as lively and just as memorable moments of frustration when no matter how many telephone calls or emails we exchanged, we couldn’t quite get that sentence right . . . but often, eventually, we did,” she said. “‘What do you do?’ someone asks me. ‘I’m a copy editor,’ I say. Some people assume that makes me Maxwell Perkins. Some assume it means I push commas around. ‘Can you really make a living at that, since everybody has spell check?’ some ask. But most authors know who does what and why. They’re oh-so-good at paying attention, too. Working on a book, I don’t just hope, I know, that the author will give my suggestions—about spelling and punctuation and dangling modifiers, sure, but larger questions as well—thoughtful and careful consideration, even when the response turns out to be ‘no thanks.’ And it still gives me a thrill. I have the best job in the world.”

One of the editors she worked with commented: “I think part of what made her such a beloved copy editor is that she explained why she did things very succinctly, never sounding like a professor or know-it-all—though she knew a great deal and fact-checked religiously—and queried in a voice that made her seem like such an ally. And sometimes she just lifted the writer’s spirit.”

One of her authors concurred: “I have never seen such thorough editing in all my years. She is a miracle. I do not ever want to publish another book without this lady’s work. She must have spent hours searching the internet. She became my true associate, and I so appreciate her caring and extraordinary intelligence and just plain smarts. This book would be chuck-full of unforgivable errors but for her.”

Cooper had a wide array of talents. She was an actor, appearing on Law & Order and other TV shows and in films. She was also a Jeopardy! champion, a five-day winner who later participated in four Tournaments of Champions. She was predeceased by her husband, the actor Fred Burrell.

Correction: An earlier version of this article incorrectly stated that the deceased was survived by her husband.