The Guaranty Building is a historic skyscraper located in Buffalo, New York. Designed by architect Louis Sullivan and completed in 1896, it is considered one of the first modern skyscrapers in the United States. The building features a distinctive terracotta façade and is known for its intricate decorative details, showcasing Sullivan's innovative approach to architecture. Standing at 13 stories tall, the Guaranty Building was originally constructed as an office building. It was designated a National Historic Landmark in 1975, recognizing its significance in the development of American architecture. Today, it remains a prominent example of the Chicago School style.