This style was named for the German kings of Britain from Hanover, Germany, including well-known monarchs like George III. The style is meant to manifest simplicity, solidity and superiority. Order and proportion are its hallmarks; its strength is in its simplicity. It is honest with little to hide. It symbolizes the British empire and its self definition. In general, the earlier Georgian homes had little front porch space. The Greek revival, a direct outgrowth of the neo-classical Georgian design, expanded the front porch.
The earlier Georgian style, especially in New England, was meant to isolate the aristocratic owner of the home. The home was a castle. His public life existed outside of it. The facade was straight, rectangular and solid. It was meant to keep something out. That "something" was the rabble of the working classes and peasants. Therefore, the class character of the British empire demanded a front porch that was small or even nonexistent. It was a statement of alienation from and superiority to the bulk of the population.
Georgian and Greek revival styles are neo-classical. They take their architectural cues from Greece and Rome. The Greek "revival" house was merely a Georgian home with more columns and a front porch that stretched the entire breadth of the front facade in some cases. The Greek revival style remained neo-classical, but, following close on the heels of the Georgian period with little to distinguish it except the porch, suggests a confident upper class that needs no protection from their social inferiors. The front porch, in other words, is a symbol of the wealthy and their understanding of the world around them.
In all neo-classical styles, columns are large, powerful and ever-present. The column is both a Greek and Roman design that is meant to suggest active citizenship. It implies strength as the empire is nothing but its nobility, broadly considered. These were the pillars of the empire. Endurance and victory are the old Roman and British concepts of the architectural column used most clearly in the construction of the porches -- whether large or small. In any case, these columns are a symbol of the "aristocracy" of Great Britain in the 18th century height of the empire.