Upton Sinclair

Upton Sinclair, Jr., was a Pulitzer Prize-winning American author who wrote over 90 books in many genres. He achieved popularity in the first half of the 20th century, acquiring particular fame for his 1906 muckraking novel The Jungle. It 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.
--Wikipedia