The third charter of the city of New Orleans, passed by the state Legislature in 1852 (Act #71), placed the legislative power of the municipal government in the hands of a Common Council composed of a Board of Aldermen and a Board of Assistant Aldermen. The former body included eleven members and the latter twenty-four. Each of the city's three municipal districts elected a set number of these representatives. Act #72 of 1852 provided for the annexation by New Orleans of the former city of Lafayette and further called for the election of one additional alderman and two assistant aldermen from the new Fourth District. The size of each board was to be adjusted following censuses to be taken every five years. In 1856 a charter revision changed the number of aldermen to nine and the number of assistant aldermen to fifteen.

Legislation could originate from either house, but no ordinance was binding until it had passed both bodies nor could any pass both houses on the same day. Each board appointed its own president and chose its own clerks and other officers. Impeachment power lay in the Board of Assistant Aldermen, with officers so impeached to be tried by the Board of Aldermen. A three-fifths majority of both houses was needed to override Mayoral vetoes. Sessions of each board were to be open, "except when the public welfare shall require secrecy." The proceedings of all open meetings were to be published in a local newspaper to be chosen by the Council.

On June 27, 1862, General G.F. Shepley, Military Commander of New Orleans, ordered the suspension of Common Council meetings; the legislative processes of the municipal government thus remained shut down for the duration of the Civil War. Council meetings did not resume until after the municipal elections of 1866 and the end of military rule in the Crescent City. In 1870 a new charter introduced the administrative form of government to New Orleans, with the Mayor and seven administrators, each with a separate governmental responsibility, combining to form the City Council.