He edited 40 anthologies of science fiction, one of mystery stories (co-edited with physician Noah Fabricant), wrote books on home improvement and was a freelance writer on scientific subjects as well as a published poet.
He was a book editor for Robert M. McBride & Co. and did public relations work for the Federal Home Loan Bank, the Office of Strategic Services, the Department of Commerce, the National Cancer Institute and the American Diabetes Association.
At the age of 26, while employed as an assistant manager at New York's Doubleday Bookstore, he arranged for the hardcover publication of a story first published in The Smart Set (November 1913), reprinting "A Flood" by the Irish writer George Moore in a limited edition of 185 signed copies.
In his Galaxy Five-Star Shelf column of December, 1954, he states, "...I actually did not become an earnest devotee of the form until 1944, about a year before the Atomic Age actually opened....The first item I remember reading that could be classified as science fiction was H. G. Wells' Men Like Gods, back in 1924 when I was a college sophomore.
The prominent display of Conklin's huge hardcover anthologies in the "New Titles" section of libraries led numerous American readers to discover science fiction during the genre's early 1950s boom.
Webster's study prompted this comment from Barry N. Malzberg: Groff Conklin was the most important science fiction anthologist through the years of the genre's true second generation, that point at which its previously magazine-bound masterpieces were being systematically located, aligned and placed into permanent format.