[1] Throughout the 19th and 20th centuries, the magazine published works of prominent authors and political figures, including Herman Melville, Woodrow Wilson, and Winston Churchill.

According to a 2012 Pew Research Center study, Harper's Magazine, along with the The Atlantic, and the The New Yorker, ranked highest in college-educated readership among major American media outlets.

[3] The early issues reprinted material pirated from English authors such as Charles Dickens, William Makepeace Thackeray, and the Brontë sisters.

[4] The magazine soon was publishing the work of American artists and writers, and in time commentary by the likes of Winston Churchill and Woodrow Wilson.

Mailer, William Styron, Gay Talese, Bill Moyers, and Tom Wicker declared that they would boycott Harper's as long as the Cowles family owned it, and the four staff writers hired by Morris—Frady among them—resigned in solidarity with him.Robert Shnayerson, a senior editor at Time magazine, was hired to replace Morris as Harper's ninth editor, serving in that position from 1971 until 1976.

On June 17, 1980, the Star Tribune announced it would cease publishing Harper's Magazine after the August 1980 issue, but on July 9, 1980, John R. MacArthur (who goes by the name Rick) and his father, Roderick, obtained pledges from the directorial boards of the John D. and Catherine T. MacArthur Foundation, the Atlantic Richfield Company, and CEO Robert Orville Anderson to amass the $1.5 million needed to establish the Harper's Magazine Foundation.

Under the Lapham and MacArthur's leadership, Harper's Magazine continued publishing literary fiction by John Updike, George Saunders, and others.

[13] In 2007, Harper's added the No Comment blog by attorney Scott Horton about legal controversies, Central Asian politics, and German studies.

Like "Harper's Index" and "Findings" in the print edition of the magazine, "Weekly Review" items are typically arranged for ironic contrast.

In September 1970, the magazine featured on its cover "Homo/Hetero: The Struggle for Sexual Identity,"[15] an essay written by Joseph Epstein, who expressed his negative views of homosexuality and compared it to being "condemned to a state of permanent niggerdom among men."

Merle Miller, a former editor at Harper’s, in the wake of "Homo/Hetero," came out publicly and wrote his own article, now considered a landmark of American journalism, “What It Means to Be a Homosexual” published in the New York Times Sunday Magazine on January 17, 1971.

[22][23] It was strongly criticized by AIDS activists,[24] scientists and physicians,[25] the Columbia Journalism Review,[26] and others as inaccurate and promoting a scientifically discredited theory.

Marcus had complained about the piece, suggesting the critique of #MeToo was inappropriate in light of Harper's "longtime reputation as a gentleman's smoking club"; he attributed this disagreement as a primary cause of his firing in 2018.