Final answer:
During the late Industrial Revolution, economic independence was the pivotal value influencing the middle class, defining its identity and relationship to new opportunities for wealth and social mobility.
Step-by-step explanation:
The value that most shaped the middle class during the late Industrial Revolution was economic independence. This period was characterized by a major shift away from the feudal structure of the Middle Ages to a new social order where wealth generation from industrial enterprises provided opportunities for social mobility. The middle class, which emerged during this transformation, placed great emphasis on the ability to improve one's socio-economic status through hard work, enterprise, and personal achievement. The concept of self-reliance and the pursuit of financial success became defining elements of middle-class identity.