Question: Early 20th-century American novelist Upton Sinclair explores socialist themes in King Coal and which earlier work based in Chicago?

Context paragraphs:
California gubernatorial election, 1934: The California gubernatorial election, 1934 was held on November 6, 1934.  Held in the midst of the Great Depression, the 1934 election was amongst the most controversial in the state's political history, pitting conservative Republican Frank Merriam against former Socialist Party member turned Democrat Upton Sinclair, author of "The Jungle".  A strong third party challenge came from Commonwealth-Progressive Raymond L. Haight, a Los Angeles lawyer campaigning for the political center.  Much of the campaign's emphasis was directed at Sinclair's EPIC movement, proposing socialist reforms to cure the state's ailing economy.  Merriam, who had recently assumed the governorship following the death of James Rolph, characterized Sinclair's proposal as a step towards communism.

Mammonart: Mammonart.  An Essay on Economic Interpretation is a book of literary criticism from a Socialist point of view of the traditional ‘great authors’ of Western and American literature (along with a few painters and composers).  "Mammonart" was written by the prolific muckraking journalist, novelist and Socialist activist Upton Sinclair, and published in 1925.

End Poverty in California movement: The End Poverty in California movement (EPIC) was a political campaign started in 1934 by famed socialist writer Upton Sinclair (best known as author of "The Jungle").  The movement formed the basis for Sinclair’s campaign for Governor of California in 1934.  The plan called for a massive public works program, sweeping tax reform, and guaranteed pensions.  It gained major popular support, with thousands joining End Poverty Leagues across the state.  EPIC never came to fruition due to Sinclair’s defeat in the 1934 election, but is seen as an influence on New Deal programs enacted by President Franklin D. Roosevelt.

Bubbly Creek: Bubbly Creek is the nickname given to the South Fork of the Chicago River's South Branch, which runs entirely within the city of Chicago, Illinois, U.S.  It marks the boundary between the Bridgeport and McKinley Park community areas of the city.  The creek derives its name from the gases bubbling out of the riverbed from the decomposition of blood and entrails dumped into the river in the early 20th century by the local meatpacking businesses surrounding the Union Stock Yards directly south of the creek's endpoint at Pershing Road.  It was brought to notoriety by Upton Sinclair in his exposé on the American meat packing industry entitled "The Jungle".

King Coal: King Coal is a 1917 novel by Upton Sinclair that describes the poor working conditions in the coal mining industry in the western United States during the 1910s, from the perspective of a single protagonist, Hal Warner.  As in his earlier work, "The Jungle", Sinclair uses the novel to express his socialist viewpoint.  The book is based on the 1913-1914 Colorado coal strikes and written just after the Ludlow massacre.  The sequel to "King Coal" was posthumously published under the title, "The Coal War."

The Coal War: The Coal War is a novel by Upton Sinclair.  It is a sequel to "King Coal" and documents the continuing exploits of that novel's protagonist, Hal Warner.  When Sinclair submitted the novel for publication in 1917, it was rejected as being insufficiently interesting from a novelistic standpoint.  After this, the manuscript remained in limbo until 1976, when it was finally published by the Colorado Associated University Press.  The book was published eight years after Sinclair's death.

The Jungle: The Jungle is a 1906 novel written by the American journalist and novelist Upton Sinclair (1878–1968).  Sinclair wrote the novel to portray the harsh conditions and exploited lives of immigrants in the United States in Chicago and similar industrialized cities.  Perhaps his main goal in exposing the meat industry and working conditions was to advance Socialism in the United States.  However, most readers were more concerned with his exposure of health violations and unsanitary practices in the American meatpacking industry during the early 20th century, greatly contributing to a public outcry which led to reforms including the Meat Inspection Act.  Sinclair famously said of the public reaction "I aimed at the public's heart, and by accident I hit it in the stomach."

Ben Hanford: Benjamin "Ben" Hanford (1861 – January 24, 1910) was an American socialist politician during the late 19th and early 20th centuries.  A printer by trade, Hanford is best remembered for his 1904 and 1908 runs for Vice President of the United States on the ticket of the Socialist Party of America, running next to Presidential nominee Eugene V. Debs.  Hanford was also the creator of the fictional character "Jimmie Higgins," a prototypical Socialist rank-and-filer whose silent work on the unglamorous tasks needed by any political organization made the group's achievements possible — a character later reprised in a novel by Upton Sinclair.

Upton Sinclair House: The Upton Sinclair House, located at 464 N. Myrtle Avenue, Monrovia, California, was the home of American novelist Upton Sinclair between 1942 and 1966.  It is a 1923 Neo-Mediterranean building in a district of similar houses, located in suburban Los Angeles, in the San Gabriel Valley.  Most of his later works were written while he lived here.  He had converted the rear garage into his study.  The grounds also include a concrete vault where he kept all his papers.

The Goose-Step (book): The Goose-step: A Study of American Education is a book, published in 1923, by the American novelist and muckraking journalist Upton Sinclair.  It is an investigation into the consequences of plutocratic capitalist control of American colleges and universities.  Sinclair writes, “Our educational system is not a public service, but an instrument of special privilege; its purpose is not to further the welfare of mankind, but merely to keep America capitalist."  (p. 18)

Supporting paragraphs: King Coal The Jungle
Answer: The Jungle