ew Orleans architecture spans over 300 years of history and encompasses many styles. It is more than just houses and churches; it is a living chapter in the changing story of this intriguing city. The French Quarter today, however, only exhibits about 80 years of architecture despite its 300 year age. This is due to the frequent disasters that the city has gone through, rebuilding itself over and over again. The fires of 1788 and 1794 have left just one building, the Old Ursuline Convent (1745), from the French Colonial period of the early and mid 1700s. The majority of the buildings visitors see today are in fact from the Spanish colonial period. The major attractions like the Cabildo, St Louis Cathedral, the Presbytere, and the Pontalba Apartments all date from this period or later. The present Cabildo or government house is actually the third built on the site by the Spanish, in 1796, as the first two were destroyed by both fires. The Presbytere, or priests' house, was likewise rebuilt in 1813 from an earlier structure that was destroyed by the 1794 fire. St Louis Cathedral is the third chuch to occupy this site, since the first two were destroyed by the hurricane of 1723 and the fire of 1788 respectively. It was completed in 1794 and given it's present facade in 1851, after the territory had become part of the United States. The Pontalba Buildings, the oldest continuously occupied apartments in the country, were built about the same time the cathedral was remodeled. Even with all the rebuilding, remodeling, and redesigning that took place over the years, however, the Old Quarter still retains its old world charm.

Jean Baptiste Le Moyne, Sieur de Bienville, the founder of New Orleans, knew that he would have to rely on the materials at hand in order to build this city. First, with the help of his engineers, he laid out a city plan similar to other outposts in Louisiana, a simple grid of streets surrounded by a wooden palisade to protect it. French Colonial Period dwellings were primitive structures at first, but later were constructed of briquette' entre poteaux or bricks between posts, a method that used wood timber framing with clay bricks inserted between them. This provided a more solid structure and was easily made, the clay sometimes mixed with horsehair. Wide galleries were added to the front and sides for cooling, and a hipped (sloped on all four sides) roof covered both the house and galleries in order to keep it dry in the second wettest city in the country. One of the best examples of this design is seen in Madame John's Legacy, a residence built in 1788 during the Spanish colonial period. It was built on a raised basement but this was not generally typical of French Quarter structures but of "country houses", since there was no great danger of flooding inside the city's levees.

The Spanish Colonial Period saw little changes in the architectural style of the Vieux Carre, aside from minor differences. After the two fires, the Spanish rebuilt the city, keeping the French style for the most part, but adding some extra elements of their own such as wrought iron grillwork (later cast iron was used), walled-in patios and courtyards, and tiled roofs (required by the new fire code). This rebuilding, combined with some remodelling of existing buildings, created a kind of French/Spanish variety of architecture that exists nowhere else in the country. An interesting and predominant feature of many houses was the porte cochere' or covered carriageway. This carriageway led through an arched opening to the rear of the house, passing by a side door that the passengers could enter during inclement weather.