Which building is an example of early steel-frame construction in Chicago?

The Home Insurance Building is widely recognized as a pioneering example of early steel-frame construction in Chicago. Designed by architect William Le Baron Jenney and completed in 1885, it is often considered the first modern skyscraper due to its innovative use of a steel frame that supported the structure's weight, allowing for greater height and an open floor plan. This construction method represented a significant departure from traditional masonry buildings, allowing for larger windows and more light, qualities that became hallmarks of modern architectural design.

In contrast, the Willis Tower and Hancock Center, while iconic structures in Chicago, represent advancements in construction technology that came after the Home Insurance Building. The Lyric Opera House, primarily a performing arts venue, does not exemplify the early use of steel-frame construction, as its architectural style is rooted in different historical contexts and design priorities. Thus, the Home Insurance Building stands out as a key milestone in the evolution of skyscraper design and the use of steel in architecture.