The first emperor of Rome, Augustus, exploited architecture to convey his sophisticated propaganda. He famously boasted to have found Rome a city of brick, and left it a city of marble. This claim has been considered an apt metaphor for the establishment of an imperial state, though the quantitative, physical veracity of the boast has never been fully interrogated. A team from UCLA mapped and modeled the marble projects added to Rome in the decades of Augustan power, using rule-based procedural modeling to generate numerous 3D, interactive, geo-temporal simulations of the entire cityscape with each marble intervention placed in situ topographically and chronologically. Broad, pan-urban views of the city’s evolution revealed that Augustan marble projects were neither overwhelming in number nor readily visible. Examination of the urban experience over time and space, however, revealed that marble construction had a constant and pervasive impact. Daily urban residents found their movements blocked by marble transports and their senses bombarded by the noisy, dusty work at construction sites. Thus, it was not the rhetoric conveyed by architecture that justified Augustus’ claim, but the rhetoric of the building act that spoke loudly and persuasively in situ.