Have you ever needed to know what the county boundaries were like in NY in the 1920s? Were they the same as they are today? Are they different? We all know that county boundaries are still fairly dynamic even today, and the need for a database that records these past boundaries is sometimes essential to GIS projects. I know a lot of times when GIS folks collaborate with colleagues in the History discipline, for example. I know I have worked on several projects were I needed to know historic boundaries for different time periods for various states, as the modern state boundaries just didn't suit the project. Sometimes I even had to digitize the boundaries from old maps...ouch..painstaking! Well search no more my fellow G.I. Scientists! We now have the Newberry Library's Atlas of Historic County Boundaries. This amazing dataset documents the county, parrish, and other boundaries for all of the states! Somebody must have spent A LOT of time creating this data! You can download the data in a variety of different formats: PDF, Shapefile, or even KML. For many of my projects I prefer to use Shapefile, because all of the county boundaries are embedded within each other. Fo
r most of my projects, I needed to select out the counties and the time period you need in order to get the data into a more usable format. For example, if I want the 1800 South Carolina counties, I would need to query those counties from the SC Database (see right).
r most of my projects, I needed to select out the counties and the time period you need in order to get the data into a more usable format. For example, if I want the 1800 South Carolina counties, I would need to query those counties from the SC Database (see right). Each state has it's own dataset and includes 5 contents:
1. Historical Counties Shapefile
2. Small Changes Shapefile (points of changes that are too small to document)
3. Comprehensive database for all historical data
4. Copies of historical chronologies
5. Copy of the Free Access Attribution-NonCommercial ShareAlike Creative Commons License
(Metadata is also available!)
So...download your state! See how far the data goes back and how your state has changed! Also a nifty data source if you are working on a historic project where modern counties are just not accurate!
Have fun :-)
