I don't know who taught that cracker octagon.........but the blacks probably built the Octagon in DC......just south of Geo. Wash U.......here in DC.....

The Octagon House
Website
Directions
Museum
The Octagon House, also known as the Colonel John Tayloe III House, is located at 1799 New York Avenue, Northwest in the Foggy Bottom neighborhood of Washington, D.C. Wikipedia
Address: 1799 New York Ave NW, Washington, DC 20006, United States
Established: 1970
Hours: 
Closed today · Hours
Phone: +1 202-626-7439
Architect: William Thornton