According to Business Insider:
We worked with individual-level responses from 2013, assembled and processed by the Minnesota Population Center’s Integrated Public Use Microdata Series program. We found the most commonly held occupation among people who responded that they were born in a country other than the US.
Now a lot of these jobs are kind of expected: farm workers along the West Coast, housekeepers throughout the South. But what’s up in Missouri, Ohio, Michigan and Maine? College professors are pretty prestigious jobs. Are American-born academics not interested in those states. And can people in Vermont, Kentucky and West Virginia not count? Why the influx of cashiers there?
The map raises a few questions but provides a lot of answers.