Upton Sinclair Jr. 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 20th 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 labor and sanitary conditions in the U.S. meatpacking industry, causing a public uproar that contributed in part to the passage a few months later of the 1906 Pure Food and Drug Ac