One hundred years ago, a book was published that changed history. It was called The Jungle. Its author was a twenty-something socialist. And its message was simple: America’s meat industry was corrupt, exploiting its workers and churning out food that shouldn’t be eaten.

The novel focused on overworked immigrants, but readers fixated on details about meat production. Upton Sinclair described men falling into vats and then being turned into food. He documented rats scurrying onto piles of diseased meat. “Rats, bread and meat would go into the hoppers together,” winding up on dining tables. This was muckraking at its best, ripping aside the veil for Americans to see what might otherwise be ignored.

Sinclair was summoned to the White House by Teddy Roosevelt. While the President slammed his fist on the table and condemned corruption, he also made it clear something would be done to address The Jungle. Sinclair had successfully turned literary celebrity into political clout. And on June 30, 1906, the Meat Inspection Act passed, “the most pronounced extension of federal power ever enacted,” its chief proponent declared.

It’s easy, looking back, to remember The Jungle as a great book, written by a great hero of the American left. Think of it: A writer uncovers injustices, publishes a book and presto, progressive legislation follows. But The Jungle did not cause the Meat Inspection Act any more than Edward R. Murrow caused the downfall of Senator Joe McCarthy. History is more complex than that.

Numerous things were in place before The Jungle: nutritional studies that explained the dangers of tainted food, previous legislation aimed at regulating meatpacking, a “progressive” President intent on taming unregulated capitalism. Other critics had already attacked the meat industry for charging high prices to consumers while underpaying cattle suppliers and workers. The Jungle helped push public opinion where it was already heading.

If we shouldn’t overvalue it, how should we remember the novel?

Not as great literature. The novel is overwrought and overwritten. It’s easy to believe the bad things documented in the book could happen, but it’s hard to believe that everything bad happens the way it does to the central character, Jurgis: practically every woman in his life becomes a prostitute, his only kid drowns in the city’s streets, and he loses his house and countless jobs. Then he converts to socialism and experiences an epiphany that seems downright goofy, with the “sky” splitting “above him” and “all the pillars of his soul” falling in.

What’s more, while Sinclair did use his fame for the cause, he allowed himself to become the center of publicity. Pursuing celebrity status, he tried to push his books more than push a movement.

Sinclair’s hunger for publicity left him open to attack–including a very recent one from America’s right-wing intelligentsia. About twenty years after writing The Jungle, Sinclair wrote Boston, a historical novel about Sacco and Vanzetti, the two Italian anarchists put to death by the State of Massachusetts in 1927. A recently discovered letter, which reflects rather cynically on the idea that the anarchists’ innocence would be better for book sales, has been seized on as evidence that Sinclair covered up his knowledge that Sacco and Vanzetti were guilty. Both Jonah Goldberg and the editors of The Weekly Standard zeroed in on a passage in which Sinclair explains that Boston would be “much better copy as a naïve defense of Sacco and Vanzetti because this is what all my foreign readers expect, and they are 90% of my public.” From this, the Weekly Standard editors concluded that Sinclair decided to “lie so his fans would keep buying his books.”

Of course, the letter doesn’t prove that Sinclair actually decided to write Boston as a “naïve” account. In fact, the novel openly discusses perjury on the part of the defense. And many of Sinclair’s letters (all available to the public) admitted, to the chagrin of his communist friends, that Sacco might have been guilty. Nonetheless, Sinclair’s slavish pursuit of book sales leaves him open to the right’s trumped-up charges.

Sinclair didn’t lie, but neither was he a “liberal saint” (Goldberg’s term). This was a man unwilling to compromise, who in 1906 said he had regrets about The Jungle‘s impact. The Meat Inspection Act was “admirable,” he grudgingly admitted, but it didn’t commit Americans to socialism–the only real solution for Sinclair. It was all or nothing. Indeed, after the Jungle sensation, Sinclair tried to create a little private utopia at his abode, Helicon Hall, with a small number of like-minded people. Then he embarked on a bizarre string of dietary experiments, trying to find what he called “perfect health.” Instead of political change, he settled for private utopia.

So do Sinclair and The Jungle leave behind anything recoverable? Yes, and Sinclair realized just what during the cold war. More conservative by the 1950s, he was embarrassed that of all his books, The Jungle was the only one still read. Communists were using it to publicize injustices of the “free world.” Sinclair explained that “America has changed a lot since” The Jungle, and “the ‘critical authors’ had something to do with that change.” He realized now that unions and federal regulations really had accomplished something.

For America to lead the battle against communism, as Sinclair thought it must, it needed to make its own institutions worthy of respect and to listen to its critics. Only then could the country win the world’s admiration. Remembering the very real sores in our past helped do this.

That’s a crucial lesson to remember in George W. Bush’s America. The world today distrusts America’s foreign ambitions, and when it peers over our borders it sees the injustices of Katrina’s wreckage and questions our commitment to democracy. The Jungle and its author’s recollections of its impact during the cold war prompt a broader lesson: The best way to nurture pride in America is to see its underbelly–past and present–and tell the truth about it.