A History of Philadelphia Churches through Maps, Part II

In the first part of this series, I discussed how distribution of churches across the Philadelphia region ties to population density, suggesting that visual patterns in maps can be used to better understand slices of our history. This material isn’t particularly novel and tells stories that are fairly well known; my interest is driven in part by a desire to explore what new things the cutting edge new technology brings us, and to help people use these technologies to get a pragmatic handle on issues which are often difficult emotionally (the inevitable changes to beloved institutions, buildings, businesses and schools which come with major social or technological change).

In this article, we’re going to continue looking at the Archdiocese of Philadelphia, primarily because of data availability, but as noted before, this will be expanded.

One of the things I noticed on moving to Philadelphia was that nearly every neighborhood claims that either George Washington or Benjamin Franklin lived there. Perhaps they had a lot of houses. The church which claims the title of oldest Catholic church in Philadelphia is Old St. Joseph’s church, a Jesuit community founded in 1733, when Franklin would have been in his early thirties. The oldest church in my data is St. Agnes of West Chester, founded in 1793 – reflecting the difficult challenge of getting a data set for this kind of thing that is even remotely accurate.

I thought as a default position that it might be interesting to plot locations by age, a generation at a time- the darkest in this represents the oldest (Ctrl-Click to enlarge).


This to me is basically useless, I was hoping to see clusters of colors, although the church does not make rapid changes – it does not seem that any event nearing the significance of Vatican Council II has happened since it completed in 1965 (this based on my completely unscientific survey of what my issues my Catholic friends and family get worked up over).
With that in mind though, let’s consider which churches were built since Vatican Council II:


I don’t think this has anything to do with church reforms; with a few exceptions it looks like they just build around the edges in a fairly even fashion. This is consistent with the accepted narrative of Philadelphia history, that over time people move from the center outwards. Notice that three are right on the edge of the city – perhaps reflecting the appeal of reducing one’s taxes by moving a couple miles.

On the other end, we can look at churches built prior to the Civil War. This proves significant in the history of Protestant churches, as many split along North/South boundaries. What I find interesting here is that the construction forms four spoke around the city center. The right-most spoke appears to follow the Delaware river, and the second spoke from the left appears to travel Schuykill river – I’m not sure about the other two.


Clearly the popularity of cars makes a huge difference: if you don’t like any institution in your area, be it a church, restaurant, or school, you can drive to the town next door. Additionally, it causes parking to become a significant zoning issue. Mass European migration to the region was also a factor: those of my grandparent’s generation remember how each ethnicity (Irish, German, Italian, Polish) had their own parish, leading to a lot of churches that were less than a mile apart and later redundant.

In researching this, I found that while cars started to become very popular in the 1920’s, they don’t seem to have become completely ubiquitous until the 1930’s. Interesting corollaries to this, from Wikipedia: “In 1919, 90% of cars sold were open; by 1929, 90% were closed.[5]”, and “. In 1930, Ford introduced the Model A, the first car with safety glass in the windshield.[8] Ford launched the first low priced V8 engine powered car in 1932.” Which suggests that cars of the 1930’s were much more practical, allowing people to travel more and further.

This final illustration shows churches built since 1930 in red: see how they are spread out, where the green points are tightly clustered.


On the article which precedes this, a friend of mine noted that churches are sometimes referred to by the predominant fuel used in the period in which they were built (e.g. coal-era churches, for those which predate cars). This chart (source: U.S. EIA) illustrates this, albeit in an odd way (The Economist, which has discussed this subject in depth, has much better charts).


See the major dip in coal use around the early 1930s. Coal appears to eclipse wood a decade or so past the Civil War – a nice a posteriori confirmation for the techniques used above, considering I didn’t see this chart until I’d finished the article.

My principle focus in building out this piece has been experimenting with maps – if you’re interested in this, I recommend checking out Tilemill, a slick piece of free mapping software. The data I’ve obtained is collected using various scraping techniques which I’ve covered previously.

If you’re enjoying this series stay tuned- the next article will discuss immigration into and within Philadelphia.