As part of his trade war with Canada, Trump has now renamed Lake Ontario to Lake America. I'm not alone in seeing this as a petty distraction from the major problems that the United States (and the world) currently faces. And it did mean that Alexandra Petri wrote a very funny article in the Atlantic about where this is all going (https://www.theatlantic.com/newsletters/2026/08/everything-called-america-now/688443/?gift=oY9TCwcAO4lary6E0C-eKedgwRiiT0yXIJ1k8taeoFE&utm_source=copy-link&utm_medium=social&utm_campaign=share).
But I did start to wonder about place names in the United States — how often do they change, when were they changed, and who has typically decided that they should change?
This week, we'll thus look at data from the US Bureau on Geographical Names (BGN), learning about various place names in the United States, what they're named, and when they were most recently changed.
Data and six questions
The data itself comes in the form of two large database files:
- The main data, with names: https://prd-tnm.s3.amazonaws.com/StagedProducts/GeographicNames/DomesticNames/DomesticNames_National_Text.zip
- Historical data (i.e., the history of the location, not of changes): https://prd-tnm.s3.amazonaws.com/StagedProducts/GeographicNames/Topical/FeatureDescriptionHistory_National_Text.zip
The data dictionary is also downloadable from AWS, at https://prd-tnm.s3.amazonaws.com/StagedProducts/GeographicNames/GNIS_file_format.pdf.
Paid subscribers, both to Bamboo Weekly and to my LernerPython+data membership program (https://LernerPython.com) get all of the questions and answers, as well as downloadable data files, downloadable versions of my notebooks, one-click access to my notebooks, and invitations to monthly office hours.
Learning goals for this week include working with CSV files, dates and times, joins, grouping, and plotting.
Here are my six questions and tasks for this week. I'll be back tomorrow with my solutions and explanations.
- Read the main name data into a Pandas data frame, making sure that the date columns are all handled as dates. Where we have information about the authority under which information was updated or changed, how many were done under each authority? How many updates have been made by executive order, and when were those made? How many lakes in the United States have the name "America" in them?
- Create a bar plot showing the number of changes to this database that were made in each year. Any thoughts about particular years? Take the largest year and count records by exact date — what does that tell you about how the database is maintained?