Question

The United States became a society of consumers in the late nineteenth century. What was the key factor that made that possible ?

I have to write a response for this, but i'm confused. It uses proper grammar and punctuation.

Answer 1

People become consumers when they have <b>money</b> in their pockets or <b>items of value</b> to trade. What was happening in the US in the late 19th century that put extra money and/or goods in many people's possession?

Also, think about why D is the correct answer for your later question:
https://www.jiskha.com/questions/1818179/what-was-one-reason-why-cities-grew-rapidly-in-the-united-states-as-a-big-business-a