Here's a bit of a historical look at map making using Detroit as an example.

Long before satellites and cameras, the Earth was being mapped with nothing more then pen and paper and a really high point. Usually this was a tall hill, then they started using hot air balloons. Now, its done with satellites, Google cars and even drones.

So, what does Detroit look like now?  Check it out here.

You can also see more Cities across Michigan that are now available in 3D here.

Google maps, 3-D