In July, 1975, the state legislature passed Act 804, authorizing municipalities, parishes, incorporated towns, etc., to establish historic preservation districts and to create preservation district commissions "for the purpose of preserving buildings, sites, structures, monuments and areas of historic interest within their respective borders with the power to enact rules, regulations and measures for the protection of the same. . . . " Several acts passed earlier in the 1970s had empowered the creation of such preservation districts but had not given commissions the authority to designate landmarks. In New Orleans, the Historic District Landmarks Commission was first established by ordinance 5643 (MCS), passed on February 20, 1975. But it was not until after the passage of the strengthened State Act 804 and the passage on June 24, 1976, of ordinance 5992 (MCS) that the commission was able to begin functioning fully. Two years later, the Central Business District was created by ordinance 6699 (MCS).

The two commissions, which share office space and staff, are responsible for preserving and protecting the architectural character of the City of New Orleans through the regulation of locally designated historic districts and the designation and regulation of separate landmark structures. The jurisdiction of the commissions includes all exterior architectural features of structures within their respective areas.

The Historic District Landmarks Commission is composed of 15 members, appointed by the Mayor, serving four-year terms. The appointees must be electors and residents of Orleans Parish; each of the designated historic districts is represented by at least one commissioner who resides or owns property in that district.

The Central Business District Historic District Landmarks Commission is composed of 11 members, also appointed by the Mayor and also serving 4-year terms. These appointees must be electors, residents of Orleans Parish, and the must be property owners or have their principal place of business in the CBD.