Delineating the spatial extent of urban phenomena at different scales is one of the core challenges researchers, planners and policy makers are faced with. This paper proposes to use satellite-derived building footprints and a clustering approach to create a hierarchy of parcels of urban land in the contiguous United states. This hierarchy is used to analyse three urban phenomena - urban form, urban spatial extent and megaregional integration. The most stable parcels from the hierarchy capture 79% of the US population and are similar to census defined urban centres. Furthermore, the hierarchy is used to show the decentralised urban form of these parcels. Lastly, the hierarchy is used to measure the morphological integration of the parcels into large scale urban phenomena - megaregions.