While most people credit The Jungle for exposing the horrible, unsanitary practices of America's meat-packing industry at the turn of the 19th century, the story spends far more time on the slum conditions and employer abuses heaped upon the immigrants who worked in the slaughterhouses and packing houses at that time. Sinclair wrote Jimmie Higgins in response to the First World War. He broke with the main body of the American Socialist Party at that time, favoring U.S. involvement in WWI, because of the threat of German militarism. After the war, however, he opposed any interference to the developing Bolshevik regime in Moscow. Upton Sinclair was one of America's most prolific writers -- by the time of his death in 1968, he had written and published millions of words and dozens of books. Although some readers feel that the character of Jimmie Higgins is not one of Sinclair's more convincing portrayals, the story of a war protestor and hero remains relevant today.

Upton Beall Sinclair Jr. (1878 - 1968) was an American writer who wrote nearly 100 books and other works in several genres. Sinclair's work was well-known and popular in the first half of the twentieth century and he won the Pulitzer Prize for Fiction in 1943. In 1906, Sinclair acquired particular fame for his classic muckraking novel The Jungle, which exposed conditions in the U.S. meat packing industry, causing a public uproar that contributed in part to the passage a few months later of the 1906 Pure Food and Drug Act and the Meat Inspection Act. In 1919, he published The Brass Check, a muckraking exposé of American journalism that publicized the issue of yellow journalism and the limitations of the "free press" in the United States. Four years after publication of The Brass Check, the first code of ethics for journalists was created. Time magazine called him "a man with every gift except humor and silence". He is also well remembered for the line: "It is difficult to get a man to understand something, when his salary depends upon his not understanding it." He used this line in speeches and the book about his campaign for governor as a way to explain why the editors and publishers of the major newspapers in California would not treat seriously his proposals for old age pensions and other progressive reforms. Upton Sinclair was considered a force of nature -- being not only prolific in his novel-writing but a political force of decided influence. Unknown to many of his admirers, Sinclair also wrote adventure fiction, under the name Ensign Clark Fitch, U.S.N.