Book excerpt: This book is part of a new generation of work on the events of the 1920s and 1930s, one that provides a gestalt view of this period. As such, the many events that have until now been viewed as unrelated, are viewed as parts of a greater whole, namely the introduction of a new power drive technology in the form of electric unit drive and its effects. The Roaring Twenties, the spectacular growth of the 1920s, the Smoot-Hawley Tariff Act, the Stock Market Boom and Crash, the decline in investment expenditure, the ensuing depression and the National Industrial Recovery Act are all shown to be related.