Google’s user-created custom maps have produced a number of fascinating and bizarre guides to restaurants, public schools and even fallout shelters. Custom maps are easily created by adding user-defined points onto the familiar Google Maps layout. Data from Google Custom Maps can be exported as a KML file, capturing user descriptions as well as exact coordinates. While easily achieved, Google Custom Maps lack much of the functionality of programs such as ArcMap and Carto. As such, Google Custom Maps cannot communicate elements such as change over time as effectively as other mapping programs.

To experiment with the functionality of Carto, I worked with data from a user created custom map from Google. Mike Stabile’s “Lost Gay Bars of San Francisco” shows closed LGBT businesses in San Francisco. In addition to the author’s original research, Stabile has encouraged members of the public to suggest locations. The result is a crowd-sourced vision of LGBT history that shows the rich history of San Francisco’s LGBT communities. While the original map is easily understood, the missing functionality of Google Maps does not allow the user to highlight change over time to show how LGBT businesses concentrate and move across the city.

To work with this data, I first exported Stabile’s map as a KML file and then converted to CSV. This allowed me to edit the data in Excel. By reviewing all of the entries, I was able to make a new column that included a date from the description to help place the location in a timeline. As the descriptions vary in terms of content, the data is limited in only showing the general era for each business rather than a precise opening or closing date. Data that did not include a date in the description was removed for this exercise.

The first map shows the location of businesses from Stabile’s original maps with color coded categories showing the decades associated with each location. By working with Carto’s formatting options, I allowed users to click on each entry to see the name, date and description associated with each closed business. The map includes many legendary local sites for LGBT history including Compton’s Cafeteria, the location of the famous riot against police harassment of transgender patrons in 1966.

While this map begins to show the way LGBT businesses moved across the city throughout the years, I thought it might be interesting to animate this data for a more compelling visualization. As historians such as Nan Boyd have pointed out, the Castro has not always been the center of LGBT business in the city. North Beach as well as Polk Street are historically significant centers of LGBT life in San Francisco. The following animated heat map helps illustrate this shift.

Consistent with historical accounts of LGBT life in San Francisco, the earliest businesses appear in North Beach and the Tenderloin. The Castro does not appear as a major hub until the 1970’s. The enhanced functionality of Carto is especially helpful in showing the timeline of these businesses as a proxy for LGBT communities. While the data used here is certainly limited, it does present a compelling story about the history of San Francisco.