[Contributor: Erik Feiereisen]
Where did the people living in Weld County come from? Let’s first look at a map showing the origins of those born outside of the United States:
Clearly, Russia was a significant place of origin. Other important countries of origin were Sweden, Germany, and Mexico. (You can hover over specific countries on the map to see the exact numbers.) This map can also tell us that there were no immigrants from Africa in Weld County in 1920.
There were a few immigrants listed as being from “South America,” but no country was specified, so we decided to leave them unplotted. We had to make some other adjustments, too, as some of the data was inconclusive. One change was that the data showed that a total of 17 people came from Australia and New Zealand, but not how many came from each country respectively. We decided to just clump them all into Australia as it was easier to see. There were also other oddities, like one person simply being listed from “Eastern Europe.” Since it was only one person, we decided to leave them off the map as there were too many countries to choose from. This was the same with immigrants from South America as the data said that they were only from South America and not a specific country.
What about U.S. states? Here’s the map of birthplaces in the U.S. (note that Colorado is removed from the data because it is too dominant, if we included it the color scale would not be sufficient to show differences between the other states):
Besides showing the states in which people in Weld County were born, this chart also neatly displays the westward migration: most people not born in Colorado were born in the states just east of it, particularly Missouri and Nebraska. We could perhaps try further analyses, looking e.g. at where these people’s parents were born, and trying to see if there is a consistent westward migration pattern in that.