Originally two courtrooms and a corridor, the City Council Chamber was reconfigured in 1897 to provide an adequate meeting space for the City's newly created bicameral legislative body, consisting of the Municipal Council and the Board of Alderman (renamed the City Council in 1938). At that time, the room was called the Aldermanic Chamber.
John H. Duncan, the designer of Grant's Tomb, led the redesign. Work was completed in less than three months, in time for the consolidation of the five municipalities into Greater New York. When Duncan combined the two courtrooms into one large room, he added mahogany paneling, a decorative plaster ceiling with bas reliefs by John Massey Rhind, ornate gilded frames, and a horseshoe-shaped spectator's gallery with an intricate wrought-iron railing. The room was also outfitted with a dais that includes an ornately carved desk, American Renaissance Revival style chair, and a decorative wooden baldachin.
In 1903, under the direction of architect William Martin Aiken, the ceiling was completed with a mural series by Taber Sears and assistants George W. Breck and Frederick C. Martin, entitled The City of New York, as the Eastern Gateway of the American Continent, Receiving Tributes of the Nations. Currently, the room is also home to portraits of the Marquis de Lafayette (1826) by Samuel Finley Breese Morse, David Thomas Valentine (1852) by Charles Wesley Jarvis, and George Washington (date unknown) by M. M. Swett, as well as the plaster model of Thomas Jefferson (1833) by David d'Angers.
As part of the 2010-2015 City Hall Rehabilitation, the City Council Chamber underwent its first major restoration in more than 50 years. The mahogany paneling and historic furniture was refinished, the walls repainted, and the balcony seating restored. In addition, as part of a public- private initiative, the Taber Sears murals were conserved, and the ceiling plaster was stabilized and repaired.
The restoration of the City Council Chamber ceiling and murals was made possible through the generous support of the Charina Endowment Fund, Gilder Foundation, Leon Levy Foundation, Municipal Art Society, Oscar de la Renta, Arthur Ross Foundation, May and Samuel Rudin Family Foundation, and Tishman Speyer Properties.