<human>:  What is the history of the middle class in America?
<bot>: The history of the middle class in America is complex and intertwined with the nation's growth and development. It is generally accepted that the middle class began to emerge in the United States in the 19th century following the end of the Civil War. During this period, Americans experienced unprecedented economic growth and industrialization that enabled more people to move up the socioeconomic ladder. As a result, the middle class began to emerge and Americans were able to purchase more consumer goods. This period is known as the Gilded Age. As the U.S. transitioned into the 20th century, the middle class grew steadily and became the engine of economic growth during the post-war period. The period saw economic expansion, with middle-class jobs increasing and more opportunities available for advancement. Following the 2008 financial crisis, the middle class has experienced a decline in their economic standing, as wages and incomes stagnated while costs of living continue to rise. Despite these challenges, the middle class is still a driving force in American economy and culture.