The catalyst for the Federal Meat Inspection Act of 1906 was the publication of Upton Sinclair's novel "The Jungle" in 1905. Sinclair's book exposed the unsanitary and dangerous conditions in the meatpacking industry, including the use of diseased animals and the presence of rat feces and other contaminants in meat products. The public outcry that followed the publication of "The Jungle" led to increased pressure on Congress to pass a law mandating federal inspection of meat products. President Theodore Roosevelt, who had read the book and was personally appalled by its revelations, also supported the legislation and signed the Federal Meat Inspection Act into law on June 30, 1906.