Define the term popular culture. Why did it become so powerful during the late 19th and early 20th centuries and how did it shape individuals’ identity?

Popular culture is a culture of mass leisure. Technology catalyzed popular culture long before the internet. Popular culture emerged in the age of the Industrial Revolution. Owing to the machines that made labor more efficient, people had more leisure time, and popular culture both resulted from the way people spent this leisure time and also in turn inspired their use of leisure time. As a practical matter, the sewing machine allowed fashions to be imitated by the middle class, rather than confined to the wealthy elite. As another practical matter, for something to be come "in vogue," a sufficient number of people need to be able to afford it. The Industrial Revolution made this possible.
Hallmarks of popular culture that emerged in the Industrial Revolution include music halls, newspaper, popular theater, vacation trips, and organized team sports. The effect on the identity of the individual is a matter of debate. On the one hand, popular culture allowed individuals to identify with a certain bourgeois class (identifiable by dress, activities, and tastes), but on the other hand, the mass consumerism to which popular culture gave rise can be said to have made people long for a more elusive sense of individuality.