The Jungle tells a fascinating but sad, and sometimes infuriating, story about an immigrant family in Chicago and the meat processing industry. It was controversial because of it’s implicit and explicit criticism of certain aspects of capitalism in America. The writer, Upton Sinclair, was himself a socialist, a form of government that does not view American capitalism kindly.
While Sinclair certainly wanted to criticize the plight of the common man in his book due to the pitfalls of capitalism, he was at the mercy of a capitalistic business model as far as publishing his novel was concerned. In order to publish a book you either have to get a publishing company to do it for you, or you have to assume the costs and do it yourself. Sinclair tried both of these avenues. Publishers will almost always ask writers to make revisions to their work to make it more commercially appealing. They are in business to make money, after all.
So publishers put the writers through an “editing” process, requiring various changes for various reasons to their manuscripts. However, this editing process is not the same thing as “censorship.” Censorship implies that a writer is being forced to change his work against his will. Publishing companies cannot do this, but they can simply refuse to publish the material. The writer is free to find other avenues of publication, including self-publication, if he can.
Some people claim that The Jungle was “censored” because certain publishers refused to publish it without changes. This is really just “editing.”
See the link below for a good discussion on this matter.