Knopf was founded in 1915 and officially incorporated in 1918, with Alfred Knopf as president, Blanche Knopf as vice-president, and Samuel Knopf as treasurer. Blanche and Alfred traveled abroad regularly and were known for publishing European, Asian, and Latin American writers in addition to leading American literary trends. Samuel Knopf died in 1932. William A. Koshland joined the company in 1934, and worked with the firm for more than fifty years, rising to take the positions of President and Chairman of the Board. Blanche became President in 1957 when Alfred became Chairman of the Board, and worked steadily for the firm until her death in 1966. Alfred Knopf retired in 1972, becoming chairman emeritus of the firm until his death in 1984. Alfred Knopf also had a summer home in Purchase, New York.
In 1923 Knopf also started publishing periodicals, beginning with The American Mercury, founded by H. L. Mencken and George Jean Nathan, which it published through 1934. Knopf also produced a quarterly, The Borzoi Quarterly, for the purpose of promoting new books.
Following the Good Neighbor policy, Blanche Knopf visited South America in 1942, so the firm could start producing texts from there. She was one of the first publishers to visit Europe after World War II. Her trips, and those of other editors, brought in new writers from Europe, South America, and Asia. Alfred traveled to Brazil in 1961, which spurred a corresponding interest on his part in South America. Their son, Alfred "Pat" Jr., was hired on as secretary and trade books manager after the war. Other influential editors at Knopf included Harold Strauss (Japanese literature), Herbert Weinstock (biography of musical jargon composers), Judith Jones (culinary texts), as well as Angus Cameron, Charles Elliott, Gary Fisketjon, Lee Goerner, Robert Gottlieb, Ashbel Green, Carol Brown Janeway, Michael Magzis, Anne McCormick, Nancy Nicholas, Daniel Okrent, Regina Ryan, Sophie Wilkins, and Vicky Wilson. Knopf also employed literary scouts to good advantage.
A publisher of hardcover fiction and nonfiction, Knopf's list of authors includes John Banville, Carl Bernstein, Willa Cather, Julia Child, Bill Clinton, Joan Didion, Bret Easton Ellis, James Ellroy, Lee H. Hamilton, Kazuo Ishiguro, John Keegan, Nella Larsen, Jack London, Gabriel García Márquez, Cormac McCarthy, Toni Morrison, Haruki Murakami, Christopher Paolini, Ezra Pound, Dorothy Richardson, Susan Swan, Anne Tyler, Andrew Vachss, James D. Watson, and Elinor Wylie. At least 17 Nobel Prize and 47 Pulitzer Prize winning authors have been published by Knopf, though they have also passed at times on subsequently notable books.
Since its founding, Knopf has paid close attention to design and typography, employing notable designers and typographers including William Addison Dwiggins, Harry Ford, Steven Heller, Chip Kidd, Lorraine Louie, Bruce Rogers, Rudolf Ruzicka, and Beatrice Warde. Knopf books conclude with an unnumbered page titled "A Note on the Type", which describes the history of the typeface used for the book. In addition, Knopf books date the year of the book's current printing on the title page.
Knopf published textbooks until 1988, when Random House's schools and colleges division was sold to McGraw-Hill.
In 1991, Knopf revived the "Everyman's Library" series, originally published in England in the early 20th century. This series consists of classics of world literature in affordable hardcover editions. The series has grown over the years to include lines of Children's Classics and Pocket Poets.