Sketch of John W. Campbell
When Campbell took over as editor of Astounding, he began to attract some of the major writers in the field, including Clifford D. Simak, L. Ron Hubbard, and Jack Williamson. The launch of Unknown strengthened Campbell's dominance of the field; Henry Kuttner, C.L. Moore, and L. Sprague de Camp contributed to both of Campbell's magazines. As well as developing working relationships with these and other established writers, Campbell discovered and nurtured many new talents. In 1938, he bought Lester del Rey's first story, "The Faithful"; the following year, he published the first stories of A.E. van Vogt, Robert A. Heinlein, and Theodore Sturgeon, along with an early story by Isaac Asimov. All these writers were strongly associated with Astounding over the next few years, and the period starting with Campbell's editorship is sometimes called the Golden Age of Science Fiction.
Heinlein rapidly became one of the most prolific contributors to Astounding, publishing almost two dozen short stories in the next two years, along with three novels: If This Goes On—, Sixth Column, and Methuselah's Children. In September 1940, van Vogt's first novel, Slan, began serialization; the book was partly inspired by a challenge Campbell laid down to van Vogt that it was impossible to tell a superman story from the point of view of the superman. It proved to be one of the most popular stories Campbell published, and is an example of the way Campbell worked with his writers to feed them ideas and generate the material he wanted to buy. Asimov's "Robot" series began to take shape in 1941, "Reason" and "Liar!" appearing in the April and May issues; as with Slan, these stories were partly inspired by conversations with Campbell. The September 1941 issue included Asimov's short story "Nightfall", one of the most lauded sf stories ever written, and in November, Second Stage Lensmen, a novel in Smith's Lensman series, began serialization. The following year saw the beginning of Asimov's "Foundation" stories, with "Foundation" appearing in May and "Bridle and Saddle" in June. Van Vogt's "Recruiting Station", in the March issue, was the first story in his "Weapon Shop" series, described by John Clute as the most compelling of all van Vogt's work.
Many of the stories from the Golden Age have demonstrated enduring popularity, but in the words of Peter Nicholls and Mike Ashley, "the soaring ideas of Golden Age sf were all too often clad in an impoverished pulp vocabulary aimed at the lowest common denominator of a mass market". Nicholls and Ashley acknowledge that, despite the uneven literary quality of the stories, the era did produce something extraordinary: "the wild and yearning imaginations of a handful of genre writers – who were mostly very young, and conceptually very energetic indeed – laid down entire strata of sf motifs which enriched the field greatly", and they consider that the Golden Age generated "a quantum jump in quality, perhaps the greatest in the history of the genre".