"What's Cooking, Uncle Sam?"
In the early 20th century, roughly 50% of Americans worked on farms. Today, more than 50% are overweight or obese. As the statistics have changed, so has the government's role in the kitchen, stockyard and grocery store. The current National Archives exhibit "What's Cooking, Uncle Sam?" tracks the relationship between the U.S. government and the food Americans eat through primary sources including public-service announcements, maps and recipes stretching back to the days of Thomas Jefferson. (To coincide with the exhibit, James Beard Award–winning chef José Andrés has opened a Washington, D.C., pop-up restaurant called America Eats Tavern, with a menu inspired by the history of American-style cooking; like the exhibit, it's open through Jan. 3, 2012.)

• Photos: A Worldwide Day's Worth of Food