This is probably the definitive book about America in the 1920s. Allen begins by describing the rather sedate and dull life of a typical couple in 1919. Then he provides a vivid account of the explosive changes of the 1920s, such as the obsession with sex, the rise of Communism, the corruption of President Harding's administration and the wild rise of the stock market. He ends the book with the mortgage crisis in Florida that led to the Great Depression. I disagreed with some of Allen's views, but this is a classic of journalism and extremely well-written.
This should be required reading in schools, I think! Perhaps we could have avoided the GFC if more people had read this brilliant book.