The original 1906 Act authorized the Secretary of Agriculture to inspect and condemn any meat product found unfit for human consumption. Unlike previous laws ordering meat inspections, which were enforced to assure European nations from banning pork trade, this law was strongly motivated to protect the American diet. All labels on any type of food had to be accurate (although not all ingredients were provided on the label). Even though all harmful food was banned, there were still few warnings provided on the container. The law was partly a response to the publication of Upton Sinclair's The Jungle, an exposé of the Chicago meat packing industry, as well as to other Progressive Era muckraking publications of the day.
The book's assertions were confirmed in the Neill-Reynolds report, commissioned by President Theodore Roosevelt in 1906. Roosevelt was suspicious of Sinclair's socialist attitude and conclusions in The Jungle and so sent labor commissioner Charles P. Neill, and social worker James Bronson Reynolds, men whose honesty and reliability he trusted, to Chicago to make surprise visits to meat packing facilities.
Despite betrayal of the secret to the meat packers, who worked three shifts a day for three weeks to thwart the inspection, Neill and Reynolds were still revolted by