For those who lived through the Great Depression, the strangeness of it was hard to convey. The nation had suffered no great natural disaster. The farmers were still farming, and the factories were still standing. Yet there lay rotting food that people couldn’t afford to buy and empty factories next to shanty towns filled with the unemployed. In 1932 Franklin Delano Roosevelt won the presidency with the promise to restore prosperity. But he and his advisers had no clear explanation for the collapse and his subsequent New Deal would amount to a series of experiments. FDR admitted to the nation...