Happy Saint Patrick’s Day! To celebrate, I have put together a visualization showing what proportion of the country reports that they are Irish in every county in American.
10.8 % of the population in the US say they have Irish ancestry according to the American Community Survey. This greatly fluctuates by county with some counties not having anyone that claims Irish roots while others have more than a third of the populations responding as Irish. Below, you are able to see a map of this statistic in all US counties, the top 5 and bottom 5 states for Irish ancestry, and a box and whisker plot of how this ranges from county to county.
The data for this visualization comes from the United States Census Bureau. It is gathered during the American Community Survey. I used 2014, 5 Year Estimates for each U.S. county. This can be found at American Fact Finder under Table B04006.
The mail version of the question that is asked is shown below as a reference. The full American Community Survey form can be found here.