industrial expansion and population growth radically changed the face of the nation's cities.noise,traffic jams,slums,air pollution,and sanitation and health problems became commonplace.mass transit ,in the form of trolleys ,cable cars,and subways,was built ,and skyscrapers began to dominate city skylines.
True, its always good to know important dates about anything, especially if it could be on a test.
To aid us in understanding a time in history
To aid us in understanding a person or culture
Many changes their minds after hearing the mayor's speech. Hope it help!