Whose 9 story skyscraper in Chicago revolutionized big city downtown landscapes?

The 9-story skyscraper in Chicago that revolutionized big city downtown landscapes is the Home Insurance Building, designed by architect William Le Baron Jenney and completed in 1885. Often considered the world's first modern skyscraper, it utilized a steel-frame construction, allowing for greater height and innovative design. This pioneering structure set the stage for the development of taller buildings and transformed urban architecture in cities worldwide.