Here's a map that tells you where exactly 341,817,095 Americans reside. The map, created by Brandon Martin-Anderson, took data from the 2010 U.S. census — and the 2011 Canadian census, but more on that below — using dots to signify where the highest concentrations of populations reside. From afar the map appears to show clumps of people concentrated in the East and West rather than individual households across the country. But when you zoom in, the precise dots become clear... as actual people. This, for instance, represents a part of Florida:
Zooming back out, you can see just how faint the population clusters end up in Canada:
Canada, like parts of the middle of the U.S., seems to barely exist.
The map, as Martin-Anderson notes in a side-bar, also yields some interesting discoveries. For instance, while a map reader may dispute that people live in certain locations—"Central Park/Pier 12/County Lockup/Abandoned Themepark"—the census did in fact report people living there.
For more details on how the map was actually made you can read here.