rench and Spanish styles contrasted with the type that was favored by the Americans who arrived in large numbers after the Louisiana Purchase. While the French and Spanish favored a more restrained and less ostentatious look to their houses, hiding their patios, courtyards, and gardens behind walls, the Americans liked to put everything up front. They liked to show off their taste with classical designs and ornamentation, and added such features as central hallways, double-hung windows, and fanlights to their townhouses. They hired prominent classical architects such as Henry Latrobe to design their homes in the new American Federal style of architecture so popular throughout the country. These new houses, built in the French Quarter and on the other side of Canal Street, started to resemble those in any northeastern city. This was the transitional period of New Orleans architecture, one in which sweeping changes in design would lead into the antebellum period.

The 1830's to the 1850's were New Orleans' golden age, when the city would become the Paris of the south. Thanks to the greater demand for cotton and slaves, New Orleans saw more wealth than ever before, and it showed in the opulent mansions that were built during this time. More elegant homes were built in this period than in any other, and since there was plenty of space to use, the rich built the largest and most extravagant homes they could afford. They hired the best architects of the time to design their houses in the new Greek Revival mode of architecture. This was a style based on Greek ruins, with large columns topped by one of three types of capitals, supporting ornate pediments and parapets. It was so popular that public buildings, churches, hotels, theatres, and even tombs were built with Greek Revival elements. Usually the houses were designed with an L-shaped plan, and built with massive stuccoed or plastered walls, two or three stories high, and either graceful columns or delicate grillwork adorned the front. The interiors featured high ceilings, and along with high double doors and tall French windows that could be opened like a door, greatly cooled the house even in the oppressive New Orleans summers.

Another architectural development concurrent with these types of dwellings was the plantation house. Although they were located mostly in the rural areas, plantations were a mainstay of the Southern economy. Growing either sugar or cotton, the plantation was virtually a small community in itself. The main house or "big house" was designed in a different fashion from the city houses. The first plantation houses were of the Louisiana colonial style, in which all their main rooms were on one floor, with a wide central hallway giving access to each room independently. The main floor was raised about eight or nine feet above the ground on a basement that usually held storage rooms, or sometimes servants' quarters or the kitchen. Both floors were surrounded on one, three, or four sides by a wide veranda or gallery supported by round columns on the first floor and slender posts on the second. Later designs followed the Greek Revival style and were very ornate, employing larger plain or fluted columns from the ground to the roof, full length square pillars, or a combination of all elements.

Many plantation houses are still scattered throughout Louisiana, but few remain in the New Orleans area. Most have been demolished to make way for subdivided neighborhoods or wider streets. Those remaining can be found on Bayou St John, near City Park, where they stand today stripped of their large tracts of land. The Pitot House is one of the best remaining examples of plantation architecture in the city. It was built in 1799 in the fashion of the early plantation houses of Louisiana, with the main floor above a raised basement and a surrounding veranda, round columns below and posts above the second floor gallery, all covered by a hipped roof. It was moved to it's present site on Bayou St John, restored by the Louisiana Landmarks Society, and opened to the public for tours. It is currently their main office.