For a while, I’ve been wanting to visualize what I know about where my ancestors lived – at least those that have been in the United States over the past 150 years or so (i.e., those for whom the U.S. census records have been particularly enlightening). Thinking about the families (and branches) and knowing that they’ve resided in various U.S. states and counties, I’ve wondered – what do those census data look like on a map?
After a bit of digging around, I found the R package USAboundaries, by Lincoln Mullen, which can map American states and counties – for any date between 1629 and 2000, using historical boundary data. (Mullen also has a book-in-progress, Computational Historical Thinking, posted on his website, which includes great tutorial worksheets for learning and practicing using R for historical and other data analysis.)
So, I tallied up census data, counting the number of my ancestral households that I have found listed in each county for each census between 1850 and 1940 (excluding 1890 – I have not found yet anyone lucky enough to have been in one of the surviving portions of that census). Here are the plots I came up with:
I found it helpful to tabulate all the census locations I had collected across the generations (for one, it highlighted at least a few gaps that need to be filled). When I finally mapped the data, though, I’ll admit, I didn’t think my maps looked that exciting at first. I mean, I knew I had had family in Delaware for quite a while, and unsurprisingly, the state’s three counties are among the most colorful these maps.
Staring at the maps a bit, though, I realize there are some aspects of my family that I’d like to know more about – for example:
- Parts of my family have been in Delaware for quite some time, but not just in one town. Based on census records, they were farmers early on, occasionally moving from town to town, county to county – sometimes back and forth within or between generations. Those that did live outside Delaware were typically in other counties in neighboring Maryland, Pennsylvania, or New Jersey. Was this typical (either among other Americans or just considering other Delawareans of these eras)?
- What living conditions or situations led my ancestors to reside where they did (either staying put or moving a short distance) across the years?
- Morris County, New Jersey is another hotspot for my family history (I had noticed it coming up repeatedly, but these graphics really hammer it home for me). I need to learn more about Morris County.
- What might a map for descendants look like? If I traced locations of descendants for one of these ancestors in 1850, would the maps across the years look this focused, location-wise; or would other lines of descendancy have dispersed out more than mine did? (I suspect at least some lines would have scattered a bit more.)
This is one reason I really enjoy putting together and visualizing data. To get some context to better understand people/families relative to others, and to come up with questions that I hadn’t even thought of before (let alone answered).