Question: How many words was the short story for which Forerunner was best known? 

Context articles: Forerunner (magazine)
Story (surname)
Guy Vanderhaeghe
Nebula Award for Best Short Story
Commonwealth Short Story Prize
The Yellow Wallpaper
Hugo Award for Best Short Story
Morgan McDermott
World Fantasy Award—Short Fiction
Eric Malpass

The Forerunner was a monthly magazine produced by Charlotte Perkins Gilman (best known as the writer of "The Yellow Wallpaper"), from 1909 through 1916.
 During that time, she wrote all of every issue — editorials, critical articles, book reviews, essays, poems, stories, and six serialized novels.
 Gilman’s drive for social change was the inspiration for "Forerunner" and its controversial articles.
 She succeeded in administering progressive ideas for change to the magazine's readers, growing support for her desires during the women's suffrage movement.
 The magazine was based in New York City.
The surname Story (and its variant spelling Storey) originates from the Old Norse personal epithet “Stóri”, a derivative of “Storr” which means “large” or “big”.
 Even though it has been established that the root of the name is “Storr”, R.E.K. Rigbeye, in his book "The Storey’s of Old" claims that the suffix “ey[e]”, in the variant of Storey, is equivalent to the Icelandic “ig” and signifies “water”.
 According to him, “Storr” also denotes large in the sense of vast and rough.
 Rigbeye’s assumption therefore, is that “Storey” means "dweller by large and rough water".
 This may be explained by the Norse affinity to sea exploration, or the fact that the first Storys settled near the Lake District, and so the name might refer to the habitation which they chose.
 The earliest Norse settlement of which the first Storys would have been a part, took place in the 9th century north of Carlisle near the Solway Firth.
 This area then known as Strathclyde, was situated in the northwestern part of England, along the Scottish border.
 The earliest Storys would have settled on the English side of the border, most likely in the plains along the river Eden.
 The English or Anglo-Saxon population, among whom the Norse settled, spoke a similar language but pronounced many words in a different way.
 So, “Storr” among the Norse would have been enunciated as “Styr” in English.
Guy Clarence Vanderhaeghe, OC, SOM (born April 5, 1951) is a Canadian novelist and short story writer, best known for his Western novels trilogy, "The Englishman's Boy", "The Last Crossing", and "A Good Man" set in the 19th-century American and Canadian West.
 Vanderhaeghe has won three Governor General's Awards for his fiction, one for his short story collection "Man Descending" in 1982, the second for his novel "The Englishman's Boy" in 1996, and the third for his short story collection "Daddy Lenin and Other Stories" in 2015.
The Nebula Award for Best Short Story is given each year by the Science Fiction and Fantasy Writers of America (SFWA) for science fiction or fantasy short stories.
 A work of fiction is defined by the organization as a short story if it is less than 7,500 words; awards are also given out for longer works in the categories of novel, novella, and novelette.
 To be eligible for Nebula Award consideration a short story must be published in English in the United States.
 Works published in English elsewhere in the world are also eligible provided they are released on either a website or in an electronic edition.
 The Nebula Award for Best Short Story has been awarded annually since 1966.
 The award has been described as one of "the most important of the American science fiction awards" and "the science-fiction and fantasy equivalent" of the Emmy Awards.
The Commonwealth Short Story Prize is awarded annually for the best piece of unpublished short fiction (2,000 to 5,000 words).
 The prize is open to Commonwealth citizens aged 18 and over.
 The Commonwealth Short Story Prize is managed by Commonwealth Writers, the cultural initiative of the Commonwealth Foundation, which was set up in 2012 to inspire, develop and connect writers and storytellers across the Commonwealth.
 The Prize replaced the Commonwealth Short Story Competition, a roughly similar competition that existed from 1996 to 2011 and was discontinued by the Commonwealth Foundation, along with the Commonwealth Writers' Prize.
"The Yellow Wallpaper" (original title: "The Yellow Wall-paper.
 A Story") is a 6,000-word short story by American writer Charlotte Perkins Gilman, first published in January 1892 in "The New England Magazine".
 It is regarded as an important early work of American feminist literature, illustrating attitudes in the 19th century toward women's health, both physical and mental.
The Hugo Award for Best Short Story is one of the Hugo Awards given each year for science fiction or fantasy stories published in English or translated into English during the previous calendar year.
 The short story award is available for works of fiction of fewer than 7,500 words; awards are also given out for pieces of longer lengths in the novelette, novella, and novel categories.
 The Hugo Awards have been described as "a fine showcase for speculative fiction" and "the best known literary award for science fiction writing".
Morgan McDermott is an American author best known for his short stories.
 His short story collection, "Owner's Manual", won the Ohio State University Prize in Short Fiction but remains unpublished.
 His short fiction has also appeared in many prominent journals and magazines including "The Nebraska Review", "The Mississippi Review", "The Bellingham Review", "Dogwood", "One Story", "Phoebe", "River City" and "New Millennium Writings".
 He has received awards for short fiction from Ruth Hindman Foundation and the Bridport Arts Centre.
 He won the Dana Award for the short story in 2002.
The World Fantasy Awards are given each year by the World Fantasy Convention for the best fantasy fiction published in English during the previous calendar year.
 The awards have been described by book critics such as "The Guardian" as a "prestigious fantasy prize", and one of the three most prestigious speculative fiction awards, along with the Hugo and Nebula Awards (which cover both fantasy and science fiction).
 The World Fantasy Award—Short Fiction is given each year for fantasy short stories published in English.
 A work of fiction is defined by the organization as short fiction if it is 10,000 words or less in length; awards are also given out for longer pieces in the Novel and Long Fiction categories.
 The Short Fiction category has been awarded annually since 1975, though before 1982—when the category was instated—it was named "Best Short Fiction" and covered works of up to 40,000 words.
 It was then renamed "Best Short Story" until 2016, when it was renamed to the "Short Fiction" category.
Born in Derby and educated at King Henry VIII School, Coventry, Malpass, while writing in his spare time, worked for Barclays Bank in Long Eaton, Derbyshire.
 He would return home after a day's work and spend the evening writing.
 He was a regular contributor to Argosy, a short story magazine although it took him many years before he was first published.
 Many other short story magazines took his work and in 1955 he won the "Observer" short story competition.
 His first book, "Beefy Jones", soon followed, and then "Morning's at Seven" which received good reviews in the UK – but poor sales – and topped the best seller list of "Der Spiegel" in Germany.
 It remained at the top of the list for three years, after which it was stipulated that no book could remain there for so long in future.
 After his initial successes, especially with "Morning's at Seven", he turned to writing full-time.
 The bank refused initially to accept his resignation, then said he would forfeit his pension and only changed its mind after very protracted discussions.
 Married, with one son, two granddaughters and five great grandchildren, he lived in Long Eaton until five years before his death when he moved to Bishop's Waltham in Hampshire.