Antebellum is unique because it's a blend of a few neo-classical predecessors. Georgian architecture in Colonial America minimizes or dispenses with entirely the columns, while French Neo-Classical tends to incorporate the colonnades directly into walls. Somewhere in the middle of those two you have the hodge podge architecture that predominates Early American and French Louisiana. Obviously, a historic Louisiana plantation is going to have more columns, particularly because of the need for large front porches and porticos, but even those columns aren't as ornate as the columns you might see in, say, Versailles.