President Eisenhower signed the bill into law with an effective date of June 30, 1960. The Act covered 80% of US plants by requiring that humane methods be used by all packing companies selling meat to the federal government. In 1978, Senator Robert Dole of Kansas and Congressman George E. Brown, Jr. of California sponsored legislation that expanded the coverage of the Act to include livestock at all plants that are federally inspected. The legislation intended to proved more effective enforcement by allowing federal inspectors to stop processing lines until any unacceptable methods are corrected. However, the economic impact of stopping a processing line is so great that inspectors are rarely able to do so. An additional requirement of the 1978 law was that any meat imported into the US must be derived from animals slaughtered in a manner that accords with the Human Slaughter Act. Final regulations under the Humane Slaughter Act were published in 1979.
