US post offices spreading over time, 1700 to 1900

Using data from the USPS Postmaster Finder and the USGS Geographic Names Information System, geography graduate student Derek Watkins maps the opening of new post offices from 1700 to 1900. As you know, the mail must go through. No matter if it rains or snows. The mail must go through. So it’s also a great way to see expansion of the US.

Some interesting spots: In 1776, after the revolution, new offices open along the east coast; in 1848, during the gold rush, offices sprout up on the west coast; in the 1870s, offices along the railroad open up.

[Derek Watkins]


  • Particularly interesting now that the post offices are closing as demand for their service goes down.

    Will be interesting to see this updated 20 years (less?) from now.

  • Little dots coming and going on the map were hard to contrast with all the random dirt on my screen. Time to clean my screen.

  • Wow. I love the railroad effect in Nebraska and Kansas. Too bad playback time isn’t directly linked to the years of the animation! Look how the decades zoom past at the beginning, masking not only the increase in the rate of population increase but also of watershed events like the gold rush, the crossing of the continental divide, and the building of said railroads.

  • Looks like someone’s just stumbled across a new instrumental variable for an as-yet-unknown endogeneity problem!

  • talk about visualizing colonization

  • Katherine Rinne August 14, 2011 at 5:11 pm

    Too bad the data is so faint that it is almost impossible to actually see the visualization. Is there a way to make this clearer/darker?