Final answer:
The primary social activity in the 19th century varied by social class, with the working class engaging in affordable entertainment like baseball, dance halls, and early movie theaters, reflecting the increased leisure time from the industrial revolution.
Step-by-step explanation:
The primary social activity during the 19th century was heavily influenced by one's social class and could include a variety of entertainment forms such as theaters, dancing, and sports. For the working class, particularly urban dwellers, inexpensive entertainment like baseball games, music halls, burlesque theaters, and dance halls were popular. Professional baseball, for example, provided affordable enjoyment and a sense of community. The burgeoning cities often offered entertainment that catered to both high culture, such as operas and ballets, and popular tastes like arcades and amusement parks. The end of the century saw the emergence of early movie theaters, targeting a wider audience with the latest technological marvels in entertainment. Ultimately, a multitude of leisure activities became available due to the increased leisure time afforded by the industrial revolution.