The document outlines significant events and developments in American cities between 1870 and 1900. During this period, elevated rail systems were introduced in New York, immigration was restricted through laws like the Chinese Exclusion Act, and the first skyscraper was constructed in Chicago. New forms of urban leadership emerged led by political bosses, and cities saw massive immigration and expansion as they became centers of industry. Urban infrastructure developed through bridges, subways, and electricity while new urban problems around housing, poverty and public health also arose during this time of rapid urbanization.