The long-standing project that led to the transfer of Brazil’s capital city, from coastal Rio de Janeiro to the country’s interior, has a legacy of information that begins with the expedition reports of 19th century geographers and that has since included 20th and 21st century urban design proposals, aerophotogrammetric surveys, spatially-defined datasets, widely published photographs, and 50+ years of satellite observation. When brought together in a relational database, disparate data streams not only produce unprecedented ways of depicting the prehistory, design, development, evolution, and projections of a city built from scratch but also set a precedent for constructing data chronologies from diverse sources. Such an integrated approach will facilitate the historical reconstruction of an entire city and provide a foundation from which to project future societal and environmental impacts as the city grows and responds to external factors. The goal of the pilotPlan Project is to create an online mapping platform that illustrates the urban evolution of Brasilia, over its entire prehistory, history, and possible futures. Primary sources, such as views, maps, architectural plans, and hyperspectral imagery are located in time and space while their associated visual and geographic data are integrated across a number of databases (including an open-access digital library of images, a geographic information system, an open source relational database, and a content delivery web service). The relationship between the various project elements will produce a web environment where qualitative and quantitative data are simultaneously loaded from an API, rendered across platforms, customized in many views, and probed by users in a system that supports multiple and interconnected expressions of diverse data sources. Scaled down into a mobile app, tourists and residents are able to walk about town while visualizing the city as it once was as well as it was once projected. Brasilia's urban history is particularly well suited to being captured in such a diachronic web map environment considering that this one city also happens to have emerged during the age of earth observation satellites and is most likely the only capital city in the world to have been observed from space, both visually and spectrally, ever since its construction.