Where We Came From: Map from NY Times

NATION ON THE MOVE 

Mapping Migration in the United States

To see Interactive Map and Story:
http://www.nytimes.com/2014/08/16/upshot/mapping-migration-in-the-united-states-since-1900.html?WT.mc_id=AD-D-E-KEYWEE-SOC-FP-DEC-AUD-DEV-DSK-1201-1231&ad-keywords=AD1214KW&kwp_0=5612&kwp_1=113727&kwp_4=43337&abt=0002&abg=0

AUG. 15, 2014

Continue reading the main story

SELECT A YEAR

1900

1950

2012

Where people who lived in each state in 2012 were born

Each shape represents where the people living in a state were born. Within a state, larger shapes mean a group makes up a larger share of the population.

 Northeast 

 South 

 Midwest 

 West 

 Outside the U.S.*

The Times has published treemaps before, as when it described how financial companies lost value during the financial crisis; it has also published Voronoi treemaps before, notably to describe inflation in 2008. But this is the first Voronoi treemap map, which uses geographic shapes as the boundaries in a Voronoi treemap.

One drawback of this technique, however, is that it’s not always possible to make each shape exactly the right size; some small values are slightly larger or smaller than they should be. (It’s either that or put holes in the map.)