Octagon Building References Octagon Building building, Washington, District of Columbia, United States Ask Anything Homework Help Written by The Information Architects of Encyclopaedia Britannica The Information Architects maintain a master list of the topics included in the corpus of Encyclopædia Britannica, and create and manage the relationships between them. The Information Architects of Encyclopaedia Britannica Britannica AI Ask Anything Learn about this topic in these articles: William Thornton…in the city, including the Octagon (1798–1800), which was used in 1814 by President James Madison after the White House was burned. The Octagon is now the national headquarters of the American Institute of Architects. Read More…in the city, including the Octagon (1798–1800), which was used in 1814 by President James Madison after the White House was burned. The Octagon is now the national headquarters of the American Institute of Architects. Read More