Sinclair went into the meat packing houses dressed like the other workers so that he could blend in and pass through the packing houses without getting caught. He slept in nearby settlement houses in order to interview the other workers who lived there..

To avoid getting caught by the owners, Sinclair remembered every thing he observed throughout the day until he got home to record his information. After 7 weeks of gathering information, he began to write the book, The Jungle.

Sinclair wrote The Jungle to expose the horrific conditions and evils in the meat packing industry. This book, published in 1906, told the stories of all the things Sinclair had observed. He described how the workers often used meat from sick animals, and how rats sometimes got ground into the meat. He compared the meat packing industry to the jungle and the workers to the animals.

Sinclair's book made the public angry about the conditions. After reading the book himself, president Theodore Roosevelt issued the Neil Reynolds report, which confirmed many of Sinclair's stories. As a result, Roosevelt passed a law allowing closer inspections of meat packing houses. This was called the Meat Inspection Act.

In conclusion, muckrakers, such as Upton Sinclair, made very important and effective changes in society. Without Sinclair, we could still have people working in the unsafe and unsanitary conditions of the meatpacking houses as they were in the early 1900's. The Jungle brought to light the horrifying truths of how this industry was corrupt for all involved and made it possible for new laws to be passed ensuring safety for workers and consumers.