Upton Sinclair, in full Upton Beall Sinclair, (born September 20, 1878, Baltimore, Maryland, U.S.-died November 25, 1968, Bound Brook, New Jersey), prolific American novelist and polemicist for socialism, health, temperance, free speech, and worker rights, among other causes. His classic muckraking novel The Jungle (1906) is a landmark among naturalistic proletarian work, one praised by fellow socialist Jack London as "the Uncle Tom's Cabin of wage...