Most people from outside New Orleans immediately associate it with the architecure of the French Quarter.
It’s worth noting that these buildings’ designs actually are mostly Spanish. In 1788 and in 1794 devasting fires destroyed almost all of the original, wood, French-built structures. Spain ran the city then. So the rebuilding–in stone–reflected a Spanish flair.
The next fun fact is that Canal Street marks a sharp architectural border.
The up-river neighborhoods rose later, under U.S. influence. The Central Business District (CBD) and Warehouse District have many late 19th- to mid-20th century buildings much like New York’s or Philadelphia’s.
Though quirk often remains.