What 10 events had the greatest impact on the meat and poultry industry during the 20th century? A survey of industry veterans and leading industry scientists by the American Meat Institute (AMI) suggests that the latter half of the century was particularly eventful. Here's a quick look back at the century that was.

1. Passage of the Federal Meat Inspection Act (1906) -- This law establishes a nationally uniform meat inspection system enforced by a single federal agency, the USDA.

2. Development of cellulose casings and skinless hot dogs (1920s) -- Machine-made, cellulose casings end the sausage industry's dependence on limited supplies of natural casings, spawning growth and price moderation in the hot dog industry.

3. Development of the refrigerated rail car/truck (1930s-40s) and a national highway system (1950s) -- The ability to transport perishable products over greater distances causes dramatic changes in meat production and distribution. Highways move plant locations closer to livestock.

4. Development of vacuum packaging (1950s) -- When combined with flexible oxygen-impermeable film, the vacuum process dramatically extends the shelf life of hot dogs and sliced meat. One result is the opening of export markets to the meat industry.

5. Growth of fast-food chains (1950s) -- The humble hamburger emerges as the icon of fast food.

6. Passage of the Humane Slaughter Act (1958) -- This law establishes uniform, humane animal handling and slaughter practices at meat packing plants, leading to safer working conditions and better quality meat.

7. Passage of the Poultry Products Inspection Act (1957) -- This law does for poultry industry what the Federal Meat Inspection Act did for red meats.

8. Development of boxed beef (1960s) -- The packing industry begins breaking up beef carcasses and shipping meat in boxes. Retailers say goodbye to heavy lifting and butchering; packers to complex shipping logistics. The result: another milestone in the marketing and distribution of beef.

9. Vertical integration (1960s to present) -- Vertical integration in the poultry industry leads to more consistent product quality and lower overhead costs, heralding case-ready products in the 1960s and branded products in the 1970s.

10. E. coli 0157:H7 outbreaks (1993 to present) -- Consumer shock and outrage over contaminated hamburger and other foods sends ripples throughout industry and government. Industry standards and practices change. Government regulations change. Customer specifications change. Everything changes.