Baltimore City Hall is the official seat of government of the City of Baltimore. City Hall houses the offices of the mayor and those of the Baltimore City Council. The building also hosts the city comptroller, some city departments and chambers of the Baltimore City Council. Situated on a city block bounded by Lexington Street on the North, Guilford Avenue on the West, Fayette Street on the South and War Memorial Plaza to the East, the six-story structure was designed by the 22-year old architect, George A. Frederick in the Second Empire style, a Baroque revival, with prominent Mansard roofs with richly-framed dormers, and two floors of a repeating Serlian window motif over an urbanely rusticated basement. The building was officially dedicated on October 25, 1875.
The site for the "new" building was selected and some designs were submitted before the American Civil War. The cornerstone for the building, under Frederick's new design, was not laid until 1867; construction was completed eight years later. At a cost of more than $2 million, Baltimore City Hall is built largely of brick with the exterior walls faced with white marble. The marble alone, quarried in Baltimore, cost $957,000. The segmented dome capping the building is the work of Baltimore engineer Wendel Bollman, known for his iron railroad bridges. At the time of its construction, the cast iron roof was considered one of the largest structures of its kind.
In 2009, a building survey found that sections of the building's marble exterior were cracked and crumbling due to age. The city approved spending $483,000 for repairs to be made the same year.