Why Los Angeles, what a big footprint you have! Created using free templates from Esri, makers of the information system considered "the standard for urban data mapping," this interactive map gives glimpses of Los Angeles at intervals between 1907 and the present, with the growth of LA demonstrated by the red blotches on the map. The maps aren't perfect—there's no explanation of why the map suddenly become yellow in the present day view, for example—but still a great way to visualize boom times.
· The Age of Megacities [StoryMaps]
· Watch Megacities Grow Before Your Eyes With These Interactive Maps [Architizer]