Smithsonian Magazine has found an interactive way to superimpose a map from 1850s over a current aerial view and it's extremely addictive. You can move this digital lens around the modern day map to see beneath it how different the city looked in the mid-19th century with this map from mapmaker James Keily. We've taken a few shots of the most interesting takeaways. For starters, the Potomac river used to be much wider...starting at the edge of the Washington Monument. As such, the spots where the Lincoln Memorial, the Jefferson Memorial and the WWII Memorial currently stand would have been underwater. Additionally, there's a divide where the tinting on the map shifts from yellow to red to indicate a different city. That different city is Georgetown which wasn't integrated into D.C. for another twenty years.
· When the Lincoln Memorial was Underwater [Smithsonian Magazine]