Elizabeth L. Eisenstein, a historian who conducted pathbreaking research into the cultural impact of Gutenberg’s movable-type printing press, and who in her later years was dubbed “the Assassin,” one of the most feared players on the senior tennis circuit, died Jan. 31 at her home in Washington. She was 92.

A daughter, Margaret DeLacy, said she had been ill but did not know the precise cause of death.

Studies of the printing press were not unusual when Dr. Eisenstein published her two-volume masterwork, “The Printing Press as an Agent of Change,” in 1979. As early as the 17th century, the scientist and philosopher Francis Bacon had considered the printing press, along with gunpowder and the compass, one of those inventions that “changed the appearance and state of the whole world.”

One of Dr. Eisenstein’s contemporaries, the Canadian philosopher Marshall McLuhan, famously observed that “the medium is the message”: that is, that the way a message is transmitted — through conversation or in print, on a digital tablet or in a podcast — crucially affects the way it is perceived. In “The Gutenberg Galaxy” (1962), he argued that movable type effectively rewired human cognition and paved the way for such large-scale trends as nationalism.

Yet no one before Dr. Eisenstein had considered the full and specific cultural impact of the printing press, said Sabrina Alcorn Baron, a visiting assistant professor of history at the University of Maryland who co-edited a book of essays about Dr. Eisenstein’s influence.

Elizabeth L. Eisenstein (Courtesy of family)

“There was really nothing before” Dr. Eisenstein’s “Agent of Change,” she said.

The interdisciplinary book — which twined such fields as the history of science, political history and bibliography, the study of books as cultural objects — centered on the relatively straightforward observation that the printing press made information more attainable, accessible and affordable.

Freed from the time-consuming, sometimes erroneous work of scribes, books and pamphlets were produced in ever-growing numbers. The result, Dr. Eisenstein observed, was a “communications revolution”: the swift spread of ideas, faster than at any previous time in human history.

The printing press, she argued, enabled such movements as the Protestant Reformation and the Scientific Revolution, allowing the arguments of Martin Luther to be widely dispersed in pamphlets and for scientists across Europe to share ideas with comparative ease.

Dr. Eisenstein had labored in relative obscurity before “Agent of Change” was published, working as an adjunct professor at American University from 1959 to 1974. The book’s manuscript provided her academic breakthrough. She was named a professor at the University of Michigan in 1975 and taught history there until retiring in 1988 as a professor emerita.

A year after retiring, Dr. Eisenstein achieved a different sort of professional peak, earning her first No. 1 ranking in tennis — as a member of the U.S. Tennis Association’s 65-and-over division.

Betty Eisenstein, as she was known on the court, played her first adult tournament in 1973, the year she turned 50. She lost — to International Tennis Hall of Fame member Dorothy “Dodo” Cheney — but quickly found her footing in a sport that she had played only briefly as a girl.

Dr. Eisenstein landed on the cover of Washington City Paper in 2005, under the headline “The Assassin.” Though 82 and standing only 5-foot-2, she was said to move “like a kid”: “She makes her opponent work so hard and hit so many extra shots that all the body blows eventually catch up to her,” the writer, Huan Hsu, said of her lethal drop shot.

In the 80-and-over division, Dr. Eisenstein was almost unbeatable, taking the 2003 national hard-court tournament without losing a single game. In all, she won 33 national tennis championships — and at one time earned 36 straight victories — before playing her last competitive match in May.

A decade before retiring from the sport, she told City Paper she was not sure that day would ever come: “Like an old war horse, you hear the trumpet and you go. As soon as I get an entry form in the mail, I forget the agony, and all I remember is the fun.”

Elizabeth Ann Lewisohn was born in New York City on Oct. 11, 1923. Her grandfather on her father’s side was Adolph Lewisohn, a prominent New York investment banker and philanthropist.

She graduated from Vassar College in 1946 and received a master’s degree in 1947 and a doctorate in 1953, both in history, from Harvard University.

In addition to her research on the early printing press, she studied revolutionary-era France of the late 18th and early 19th centuries. Her later books included such works as “Grub Street Abroad” (1992), which examined the French publishing scene in the years before that country’s revolution, and “Divine Art, Infernal Machine” (2011), a survey of the printing press’s reception through the centuries.

In 1979, she became the first resident scholar at the Center for the Book, a newly founded branch of the Library of Congress that promotes reading and the study of books as cultural objects. At the Folger Shakespeare Library, she occasionally taught courses and was a member of the board of governors.

She won an American Historical Association award for scholarly distinction in 2003.

Survivors include her husband of 68 years, Julian Calvert Eisenstein of Washington; two children, Margaret DeLacy of Portland, Ore., and Edward Eisenstein of Fayette, Mo.; a sister; three grandchildren; and two great-grandchildren.

Tennis brought her greater publicity than her research, but she approached both with equal intensity and focus.

“I often think of a tennis game as something where the two of you are trying to see who is going to control the other one’s movements,” Dr. Eisenstein said to City Paper. “Controlling a point is very important in my thinking. I get mad at myself when I lose control, so to speak.”