All that space is a sign of our times — of the relative wealth to afford it, the government policies that incentivize it, the tastes we now have for third bathrooms and fourth bedrooms (even though the size of the typical American household has actually been shrinking).
In fact, in many ways — most of them more subtle — the American single-family home has changed with time in ways that say much about us and how we live. Vertical town houses built in the 1800s gave way a century later to horizontal homes, 3,000 square feet on a single floor. Compact ways of living that made sense when we got around on foot faded with time in favor of the spacious homes made possible by ubiquitous cars. And the popularity of cars changed the very design of our homes, too, as we created places to park them indoors.
We've gone over time from the row house to the ranch home to the McMansion, with myriad variations along the way determined by the climate (a New Orleans shotgun house demands a front porch for cooling off) and the culture (prairie-style homes mimic a favorite Midwestern son, Frank Lloyd Wright). Our homes have been reshaped, reformatted, and reimagined depending on the availability of land and the materials on offer and the earlier styles that have come back in vogue.
The evolution of the American single-family home is nicely captured on this data visualization from the wonky artists at Pop Chart Lab. Their 400-year visual history of the American home focuses on single-family houses, and so the collection skews suburban and rural; there are no apartment buildings here. But this is the housing type that's home to a majority of American families.
The visualization doesn't give a full sense of how the scale itself has shifted, too, but it shows clearly how architectural styles and details have. The full poster, based on Virginia Savage McAlester's A Field Guide to American Houses, also gives a sense of why the bland sameness of suburban subdivisions is often criticized. There is tremendous variety, and architectural heritage, in the American single-family home. (Click here for a higher resolution image.)