The growth of the US Postal Service by 1890. (IMAGE)

Proceedings of the National Academy of Sciences

The growth of the US Postal Service by 1890.

Caption

The growth of the US Postal Service by 1890. The image shows a map of the United States' more than 3,000 counties (excluding Alaska and Hawaii). Counties are colored based on the number of post offices present as of 1890. 

Credit

Image credit: Adam Ramey.

Usage Restrictions

None

License

Licensed content

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.