Towering structures made of steel and iron completely changed the way architecture was conceived in the second half of the 19th century. The skyscraper, as it came to be known, was born out of a desire for greater economy as well as to reduce fire hazards, not to mention maximize limited real estate.
Compare four (4) structures that reflect the idea and ingenuity of new architectural material that allowed the building of these towers; your dates are restricted between 1865 and 1935.
Compare these structures and the cultures/geographic areas that produced them, being sure to discuss how they are a product of their time, art/design movement, and the significance they had in influencing other architecture/architects.