The American Second Empire style has its roots in mid-19th-century Paris, when Napoleon III declared himself the ruler of France's Second Empire (his cousin Napoleon Bonaparte ruled the first) and
took measures to modernize the architecture and streets. Wide boulevards lined with mansard-topped town houses dominated the new landscape and, to this day, continue to define the city's image. Americans copied the look and adopted its name.
The Second Empire style, which lasted in the U.S. from 1855 to 1885, is characterized chiefly by the various curved and straight forms of the mansard (named for a 17th-century French architect, Francois Mansart). The style also features decorative bracketing, double doors, and narrow arched windows, all borrowed from the earlier Italianate style. Urban versions were usually plain and boxy, like the T.O.H. project house in Charlestown, Massachusetts.
Second Empires in the country, like this high-style house (above) in Mt. Kisco, NY, often displayed more dramatic and exuberant features, such as cupolas and projecting windows.
The fascination with things French,
especially the mansard roof, did wear off eventually: By the mid-1880s, Second Empire had been supplanted by the even
more daring and inventive — and English — Queen Anne style.