Further , economic prosperity led to dramatic growth of the middle class in the 1920s and after World War II .
At the same time , reforms such as labor unions rights were passed during the Progressive Era , with further reforms during the New Deal of the 1930s .
Economic prosperity led to dramatic growth of the middle class in the 1920s and after World War II .
At the same time , reforms such as labor unions rights were passed during the Progressive Era , with further reforms during the New Deal of the 1930s .