Upton Sinclair was a famous novelist and social crusader from California, who pioneered the kind of journalism known as "muckraking." His best-known novel was "The Jungle" which was an expose of the appalling and unsanitary conditions in the meat-packing industry.

Upton Sinclair (born September 20, 1878, Baltimore, Maryland, U.S.—died November 25, 1968, Bound Brook, New Jersey) was a prolific American novelist and polemicist for socialism, health, temperance, free speech, and worker rights, among other causes.