America's second war with Great Britain was declared in 1812. The following year American forces invaded Upper Canada and burned the governor's house and legislative hall in York (now Toronto). In retaliation, a British military expedition sailed up the Patuxent River aiming to destroy the public buildings in Washington.

After a brief battle British troops entered the deserted city on the evening of August 24, 1814. At the U.S. Capitol, troops came armed with gun powder and torches. Damage was heaviest in the section of the north wing occupied by the Library of Congress. The Senate and House chambers were both destroyed, yet all of the south wing's first floor rooms survived. Many of the great neo-classical designs built under President Jefferson's supervision were lost; the nation had suffered a humiliating blow to its honor.