In their quest to discover primary source documents, historians will scour special collections libraries, genealogists will read through roll after roll of microfilm, and students will keyword search through centuries old books now digitized and easily available online. While historical research may be getting much easier with the advent of dozens of digitization projects and online resources, one type of research tool often remains overlooked – maps.

Perhaps, to many people, it just seems easier to find information in documents. You locate the papers related to your topic and then read the list of names or the journal entries or the ledgers from a business. It can take a bit more time to figure out what exactly you are looking at with a map and how the street names, businesses, railroad lines, parcel outlines, and other features can assist with research. With a little effort (and online tools in some cases), maps can serve as an excellent source of historical information.

Hexamer & Locher Plate 62A, 1859

Maps provide great visual documentation for how a neighborhood, city, or other geographic area has changed over time. For a recent article on the history of Callowhill, the neighborhood in Philadelphia where Azavea is located, I turned to some excellent online maps. The Hexamer & Locher maps on PhillyHistory.org show that Callowhill was filled with small rowhouses by 1859, verifying other sources that list Callowhill as an area filled with the homes of factory workers and their families. To go beyond simply looking at land parcels and find out more specific information, I used several of the many, many maps available on the Greater Philadelphia GeoHistory Network website. The site features an extremely helpful Interactive Maps Viewer that allows users to layer historic maps on top of each other, adjust the transparency levels, and apply a current streets overlay to compare past geography to the present landscape.

Thanks to the 1895 Philadelphia Atlas developed by George and Walter Bromley, I was able to discover the names of businesses that operated in Callowhill. The Standard Iron Foundry, the Knickerbocker Ice Co., the Hoopes & Townsend Nut and Bolt Works, the First Regiment Armory, Monroe School, and dozens of other buildings are clearly labeled and outlined on the map. By comparing this map with the 1942 and 1962 Philadelphia Land Use maps, it was possible to see how the neighborhood changed over time as businesses moved, changed names, declined, and grew.

1895 Philadelphia Atlas

It seems obvious that maps provide insight into the history of a neighborhood. With a little analysis, their usefulness can extend to other research topics as well. A genealogist may locate a distant ancestor in a census or city directory from the late 1800s. If that census or directory provides an address, the genealogist can locate their ancestor’s house on a map and discover entirely new research possibilities. Did their ancestor attend the school two blocks over? Did they settle in the neighborhood because they worked at the nearby factory? Or did they use the trolley that ran in front of their house to commute to a job in another neighborhood? Maps also serve as tool for historians. Why did factories choose to start up businesses in this area? How did railroad lines and other construction projects affect the area? Why did people choose to live here? Did they have a choice or were they influenced by socioeconomic or cultural pressures?

At Azavea, we’re obviously convinced of the value of maps. We’re also doing our part to help make information about historic maps and streets more accessible. In addition to making the Hexamer & Locher maps available on PhillyHistory.org, one of our research projects includes development of a historic geocoder which would enable users to geocode historic addresses that may not currently exist under the same name.