Guaranty Building

The Guaranty Building, also known as the Prudential Building, was designed by Louis Sullivan in partnership with Dankmar Adler and completed in 1896 in downtown Buffalo, New York, as an early and highly influential example of the steel-framed skyscraper. Sullivan clad the steel structure entirely in ornamental terracotta, organizing the facade into a clear three-part vertical scheme of base, shaft and capital that visually expressed the building's underlying steel skeleton rather than disguising it behind historical masonry forms. The terracotta itself carries dense, intricate organic ornament of Sullivan's own design, incorporating foliate and geometric patterns across nearly every exterior surface, an approach closely associated with his belief that a building's decoration should grow logically from its structure and purpose. Sullivan articulated that philosophy most famously as form follows function, and the Guaranty Building is often cited alongside his Chicago work as a defining built statement of that idea. The building survives today as one of the best-preserved examples of Sullivan's mature commercial architecture and a National Historic Landmark.