Its my understanding that realism in America was a way to show the zeitgeist of the era. It was contemporary to the time.
And the time was saturated with new ethnicities and the city life. Industry and a booming economy and a new kind of freedom for urbanites! Things were starting to really pick up then and they were moving faster.
Although those realist painters like Hopper were looking at people like William Merritt Chase among others they were concerned with portraying the nowness of their time, or, again, zeitgeist. It was about city life and metropolitan living. Ill grab my history books later on and see if I'm right about it for you.
