Jane Garrett, who as an editor at the Alfred A. Knopf publishing house guided seven books to Pulitzer Prizes for history but watched another book lose its prestigious Bancroft Prize over scholars’ criticism of the author’s research, died on Oct. 12 at her home in Middlebury, Vt. She was 88.

The cause was Alzheimer’s disease, said Anne Eberle, a close friend.

Ms. Garrett worked at Knopf for 44 years, initially as an editor and special assistant to Alfred Knopf himself, who had a strong devotion to publishing history books. At first she steered his projects to completion, but she soon began acquiring books on her own.

In 1973, “People of Paradox: An Inquiry Concerning the History of American Civilization,” by Michael Kammen, became the first of the books edited by Ms. Garrett to win a Pulitzer. The next, in 1987, was “Voyagers to the West: A Passage in the Peopling of America on the Eve of the Revolution,” by Bernard Bailyn, a Harvard scholar of early American history who was Ms. Garrett’s mentor. A year later, “The Launching of Modern American Science, 1846-1876,” by Robert V. Bruce, also won.

Ms. Garrett was at a book party in Boston when she met Alan Taylor, who was starting to work on a book about William Cooper, the founder of Cooperstown, N.Y., and the father of the novelist James Fenimore Cooper. They chatted, and he sent her a proposal.

“It was pretty academic, so she asked, ‘Can you rework this and draw the characters out more?’ and I got a contract,” Mr. Taylor recalled in a phone interview. “It was the first time I got paid upfront for anything.”

Mr. Taylor later learned that Ms. Garrett had already had an interest in the Coopers, which she had not mentioned to him. While doing research in the Cooper family archives at Hartwick College in Oneonta, N.Y., he found a box with her name on it.

“She said, ‘Oh, yeah, I’m an old family friend of the Coopers,’” he recalled her telling him. A direct descendant of the family had asked her to organize the papers.

Mr. Taylor’s “William Cooper’s Town: Power and Persuasion on the Frontier of the Early American Republic” was published in 1995 and won the Pulitzer the next year.

Several books edited by Ms. Garrett also received the Bancroft Prize for American history and diplomacy from Columbia University. Two awards are given each year, and in 1996 Ms. Garrett’s authors took both: Mr. Taylor’s book and David Reynolds’s “Walt Whitman’s America: A Cultural Biography.”

Another book she edited, “Arming America: The Origins of a National Gun Culture” (2000), by Michael Bellesiles, won a Bancroft in 2001. That book’s thesis — that very few people owned working guns in colonial America — set off a furious academic debate.

Scholars documented serious errors in Mr. Bellesiles’s research and said that he had misused historical records. And those scholars who tried to examine his claim that he had studied more than 11,000 probate records — which led him to determine that only 14 percent of estate inventories between 1765 and 1790 listed guns — learned that most of those records had been destroyed in a flood.

At first, Ms. Garrett backed Mr. Bellesiles. “I realize that he made some errors, but they certainly were not made intentionally,” she told The Chronicle of Higher Education in early 2002. “They were the result of some over-quick research.”

But later that year, Columbia rescinded Mr. Bellesiles’s Bancroft, saying that his book “does not meet the standards” for the prize. Knopf cut its ties to Mr. Bellesiles in 2003, deciding to stop printing copies of the book.

“I still do not believe in any shape or form he fabricated anything,” Ms. Garrett told The Associated Press at the time. “He’s just a sloppy researcher.”

Martha Jane Nuckols was born on July 16, 1935, in Dover, Del. Her father, D. Elwood Nuckols, was an orchardist and at one time the president of the Delaware board of agriculture. Her mother, Edna (Davidson) Nuckols, was a homemaker.

“As a child, I was in a book-starved environment during World War II in rural Delaware,” she told C-SPAN in 1996. But in junior high school, she began reading Life magazine, and her father signed her up for the Book-of-the-Month Club.

She studied history at the University of Delaware and, in her senior year, married Wendell Garrett, who would become the editor of Antiques magazine. After earning her bachelor’s degree in 1957, she joined the acquisitions department of the Boston Athenaeum library. She was the assistant to the director there from 1959 to 1968.

During that time she was also a research assistant to Professor Bailyn for his book “The Ideological Origins of the American Revolution,” which won a Pulitzer in 1968.

She joined Knopf in 1967 but was not well known in publishing circles, in part because she stopped working in the company’s Manhattan office in the mid-1970s and began working at home, first in Cornwall, Vt., and later in Leeds, Mass.

“When I came in here, it was some months before I realized there was this editor who operated in the hinterlands someplace,” Sonny Mehta, then the president of Knopf, told The New York Times for a profile of Ms. Garrett in 1996. “Jane was the last person I got to know here.”

She also spent time at American history conferences and meetings, listening to papers and presentations in search of topics that could generate books.

One of those books was “Founding Mothers & Fathers” (1996), about the early settlers of colonial America, which grew out of a paper that Mary Beth Norton presented at a professional meeting. The book was a Pulitzer finalist in 1997, but Ms. Norton lost to another of Ms. Garrett’s authors, Jack Rakove, who wrote “Original Meanings: Politics and Ideas in the Making of the Constitution.”

Ms. Garrett also edited best sellers, including “A History of God: The 4000-Year Quest of Judaism, Christianity, and Islam” (1993), by Karen Armstrong, and “The Road From Coorain” (1989), a memoir by Jill Ker Conway, the feminist author and first woman to become president of Smith College.

Ms. Garrett’s other Pulitzer winners were “A Midwife’s Tale: The Life of Martha Ballard, Based on Her Diary, 1785-1812” (1990), by Laurel Thatcher Ulrich, and “The Radicalism of the American Revolution” (1991), by Gordon S. Wood.

When C-SPAN’s Brian Lamb asked Ms. Garrett in 1996 about the six Pulitzer-winning books she had edited (it was months before Mr. Rakove won the seventh), she said: “Some people think that may be a record. I don’t know. There really isn’t any way to know. And I hope I have a few more.”

Ms. Garrett had a second career in the Episcopal Church. Although she was not a seminary graduate, she read for the priesthood and was ordained by the Diocese of Vermont in 1981. Her work as a priest was mostly part time, and she was able to pursue it from home when she could take time off from editing books.

Her professional and religious roles merged in 1996 when she signed Walter C. Righter, a retired Episcopal bishop of Iowa, to Knopf to write a memoir about being charged with — and then exonerated of — heresy for having ordained a gay man as a deacon. His book, “A Pilgrim’s Way,” was published in 1998.

Ms. Garrett’s marriage to Mr. Garrett ended in divorce. No immediate family members survive.