After lawsuits by several companies against Collier's ended in failure, other magazines joined in what Theodore Roosevelt described as "muckraking journalism."

P. F. Collier & Son began in 1875, expanding into the largest subscription house in America with sales of 30 million books during the 1900–1910 decade.

[8] With the issue dated April 28, 1888, Collier's Once a Week was launched as a magazine of "fiction, fact, sensation, wit, humor, news".

It was sold with the biweekly Collier's Library of novels and popular books at bargain rates and as a stand-alone priced at seven cents.

[9] When Robert Collier died in 1918, he left a will that turned the magazine over to three of his friends, Samuel Dunn, Harry Payne Whitney and Francis Patrick Garvan.

[11] The factory complex, much of which is no longer standing (finally razed in 2020),[12] was built between 1899 and 1946, and incorporated seven buildings that together had more than 846,000 square feet (78,600 m2)—20 acres (81,000 m2)—of floor space.

Knox Burger was Collier's fiction editor from 1948 to 1951 when he left to edit books for Dell and Fawcett Publications; he was replaced by Eleanor Stierhem Rawson.

The numerous authors who contributed fiction to Collier's included F. Scott Fitzgerald, Ray Bradbury, Eleanor Hoyt Brainerd, Willa Cather, Roald Dahl, Jack Finney, Erle Stanley Gardner, Zane Grey, Ring Lardner, Sinclair Lewis, E. Phillips Oppenheim, J. D. Salinger, Kurt Vonnegut, Louis L'Amour, Albert Payson Terhune and Walter Tevis.

The Mask of Fu Manchu, which was adapted into a 1932 film and a 1951 Wally Wood comic book, was first published as a 12-part Collier's serial, running from May 7 to July 23, 1932.

Benda, Chesley Bonestell,[17] Charles R. Chickering,[18] Howard Chandler Christy, Arthur Crouch, Harrison Fisher, James Montgomery Flagg, Alan Foster, Charles Dana Gibson, Vernon Grant, Emil Hering, Earl Oliver Hurst, Alonzo Myron Kimball, Percy Leason, Frank X. Leyendecker, J. C. Leyendecker, Paul Martin, John Alan Maxwell, Ronald McLeod, John Cullen Murphy, Maxfield Parrish, Edward Penfield, Robert O. Reed, Frederic Remington, Anthony Saris, John Sloan, Jessie Willcox Smith, Frederic Dorr Steele, Emmett Watson, Jon Whitcomb and Lawson Wood.

They included Harold Mathews Brett, Richard V. Culter, Robert Fawcett, Denver Gillen and Quentin Reynolds.

Under Hapgood's guidance, Collier's began publishing the work of investigative journalists such as Samuel Hopkins Adams, Ray Stannard Baker, C. P. Connolly and Ida Tarbell.

Hapgood's approach had great impact, resulting in such changes as the reform of the child labor laws, slum clearance and women's suffrage.

This article is but the opening gun of the campaign, and is largely introductory in character, but it will give the reader a good idea of what is to come when Mr. Adams gets down to peculiarities.

The list of "tonics," "blood purifiers" and "cures" that will come under this head has not yet been published by the Treasury Department, but it is bound to include a good many of the beverages which, up to the present time, have been soothing the consciences while stimulating the palates of the temperance folk.

The next official move will doubtless be against the opium-sellers; but these have likewise taken fright, and several of the most notorious "consumption cures" no longer include opium or hasheesh in their concoction.

Writers such as Martha Gellhorn and Ernest Hemingway, who reported on the Spanish Civil War, helped boost the circulation.

Winston Churchill, who wrote an account of the First World War, was a regular contributor during the 1930s, but his series of articles ended in 1939 when he became a minister in the British government.

Frost, Ralph Fuller, Dave Gerard, Vernon Grant, Jay Irving, Crockett Johnson, E. W. Kemble, Hank Ketcham, George Lichty, David Low, Bill Mauldin, Virgil Partch, Mischa Richter, William Steig, Charles Henry "Bill" Sykes, Richard Taylor, Gluyas Williams, Gahan Wilson and Rowland B. Wilson.

The circulation battle with The Saturday Evening Post led to the creation of The Collier Hour, broadcast 1927–32 on the NBC Blue Network.

The hour-long program initially aired on the Wednesday before weekly publication, but switched to Sundays to avoid spoilers with stories that appeared simultaneously in the magazine.

Karski's book Story of a Secret State, which included the Collier's excerpt, was published later that year by Houghton Mifflin.

Collier's had a circulation of 2,846,052 when Walter Davenport took over as editor in 1946, but the magazine began to lose readers during the post-World War II years.