Close to 40 million Americans move from one home to another every year. Jon Bruner’s updated “American Migration” visualization, demonstrates how “Americans are enormously mobile: 37.5 million people moved from one house to another last year, with 4.3 million of them moving between states.”
The interactive map lets you click on a specific county and see the immigration and emigration data for that location. Bruner explains on his blog some of the more technical specifics on the creation and workings of the visualization:
For details on how he used open source tools to create the visualization, check How To Build an Interactive Map with Open-Source Tools.