In an era of smart cities and urban science, data has rapidly become king. Typically, the focus is on real-time measurement and forward-looking studies, but history also has a lot to teach us, too. However, a great deal of historical data on global urban development has been hidden in two dense and (ironically) un-digitized studies. In fact, until recently, the UN had the only geolocated data set of city growth and it only went back to 1950. Now, Meredith Reba, an urbanization researcher at Yale, has published a study plotting 6,000 years of global, city level population data. The first easily digestible research of its kind, the study not only the size of past cities, but how, when, and where they emerged. This data, which makes for an impressive visualization of humanity’s recent urbanization, and opens the door to a wide-range of new research. Perhaps most importantly, it adds valuable context to the professionalization of city making: The first urban planning program started in 1909, while architecture education at the university level was initiated in 1865. In contrast, urbanization started in 3700 BC. Stay humble, a lot happened before we started.