By: Lo Bénichou
On April 4, 1968, a short time after the murder of Martin Luther King Jr. had reached the ears of residents in D.C., riots sparked throughout the city, leaving 13 dead and 900 businesses damaged.
In an effort to contextualize the events that followed the death of MLK Jr., The Washington Post triaged data from more than 2,000 declassified Secret Service reports compiled by Brandeis University professor, Daniel Kryder. With that data, The Post created a powerful, immersive experience, combining audio interviews, archival footage, and a map built with Mapbox GL JS and Studio.
We got in touch with Armand Emamdjomeh, graphics reporter for the Washington Post, to get a behind-the-scenes perspective on The Four Days in 1968 That Reshaped DC.
“In Washington, DC, the same address can exist in several quadrants, so one of the main challenges is always making sure that addresses are geolocated correctly […] The quadrant was not always specified in the Secret Service reports, so to be certain we were representing the data as accurately as possible, some data points had to be discarded, ” says Emamdjomeh
The maps in this piece are critical to the story and enabled the team to show “the spatial patterns of how the riots spread throughout the city,” according to Emamdjomeh.
“Using Mapbox to visualize the Secret Service reports, we could show that activity wasn’t confined to the three corridors that suffered the most damage. The riots were something that were felt throughout the entire city, ” he says.
The damage after the riots was extensive. The map above uses data-driven styling to color buildings based on the level of damage. To setup the buildings layer, Lauren Tierney, also a graphics reporter and cartographer on the team, digitized and geo-referenced building footprints from DC city planning documents. You can read our step-by-step guide on how to scan and geo-reference paper documents.
You may have noticed government buildings like the Capitol are drawn on the map and resized at different zoom levels. You can accomplish this by adding an image and interpolating the icon-size property at the zoom levels you specify.
The result:
And to add historical context to the map, Tierny used Mapbox Studio to style the base layer to closely resemble government maps of the 1960s.
“We found Mapbox Studio very useful for developing and iterating on different versions of the map. We started with the Mapbox Light map style and removed layers until we had a fairly minimalist setup, then started implementing our 1960s ‘Government Chic’ style, “ Emamdjomeh explains.
Throughout the map, animated markers draw your attention to the location of incidents in the Secret Service reports. Using Mapbox GL JS and transitions, the animation can be reproduced by adjusting the circle-radius property of a circle layer. Check out our guide on how you can create your own animations.
When we asked Emamdjomeh what the team had in mind for their next project, he told us they wanted to explore creating their own tileset using tippecanoe, our open-source command line tool for building vector tiles from large collections of GeoJSON features. And they did just that…
In this mind-blowing piece, his colleague, Aaron Williams, visualized what modern segregation looks like in US cities. A technical deep-dive on how they built it is coming your way very soon…
Use Mapbox Studio to create custom maps, and use GL JS to make the experience interactive. We support powerful storytelling and data journalism — reach out to our Narratives Desk if you have questions, want to collaborate, or just want to show us what you’re working on. Contact lo.benichou@mapbox.com or @LoBenichou on Twitter.
Revisiting the 1968 D.C. Riots with maps was originally published in Points of interest on Medium, where people are continuing the conversation by highlighting and responding to this story.