Mullett left Rogers on less than friendly terms in 1860, to establish his own practice. His first known individual design is the Church of the New Jerusalem, a board-and-batten
Gothic Revival church built at Glendale in 1861. After serving with the
Union army during the American Civil War, Mullett in 1863 relocated to
Washington. He worked again with Rogers, since 1862 the
de facto Supervising Architect at the
Treasury Department. At that time the Treasury Department oversaw design and construction of all federal buildings. Influenced by the 1864–1868 remodeling of the
Louvre's
Pavillon de Flore by
Hector Lefuel and
Richard Morris Hunt, Mullett produced six massive fortress-like
Second Empire federal buildings in
St. Louis,
Boston,
Philadelphia,
Cincinnati,
New York and Washington D.C. What was called the
State, War, and Navy Building rose near the
White House. These stone and
cast iron structures, with
mansard roofs and multiple tiers of
columns, were expensive. Mullett was dogged by accusations of extravagance and subjected to five separate investigations into his ties to the corrupt "Granite Ring". In 1890, in financial trouble and ill health, Mullett killed himself in Washington. Over his career he produced some 40 government buildings. Two of the six huge Second Empire buildings survive in St. Louis and Washington. The New York City Hall Post Office was dubbed "Mullett's monstrosity." Following another shift in popular taste, however, he is recognized since the late 20th century for his contribution to monumental Victorian architecture. == Death ==