Upton Beall Sinclair, Jr. (September 20, 1878 - November 25, 1968) was an American author who wrote nearly 100 books and other works across a number of 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 remembered for writing the famous line: "It is difficult to get a man to understand something, when his salary depends upon his not understanding it."
Sinclair was an outspoken socialist and ran unsuccessfully for Congress as a nominee from the Socialist Party. He was also the Democratic Party candidate for Governor of California during the Great Depression, but was defeated in the 1934 elections.