The Cabildo. Erected 1795-1799. Don Gilberto Guillemard, architect. Construction financed and directed by Don Andres Almonester y Roxas. The mansard roof was added in 1847. The illustrious Cabildo (Spanish colonial city council) held its sessions here in the Sala Capitular from May 10, 1799 until Nov. 30, 1803. The building housed the City Hall of New Orleans 1803-1853, and the Supreme Court of Louisiana 1953-1910. Until 1914 the prison at the rear was used as a jail servicing the police station on the first floor. Louisiana State Museum since 1911. Here on December 20, 1803 were signed the documents transferring the Louisiana Purchase territory from France to the United States. In 1825 the Cabildo was temporarily converted into a fine residence for the visit of General Lafayette. On this site stood a French Colonial Corps de Garde - 1742 - and a prison and criminal court room “Chambre criminelle) - 1730. The Corps de Garde, rebuilt in 1751, burned in 1788. The remains of its massive brick walls were incorporated in the present Cabildo building in 1795. The first Cabildo was constructed here in 1769 by the Spanish Governor Don Alexandro O’Reilly and destroyed in the conflagration of March 21, 1788. Destroyed in the conflagration of March 21, 1788. Restored 1966-1970 for the Louisiana State Museum. Orleans Parish Landmarks Commission.
