We recently looked at the dominant languages in each of NYC's neighborhoods. Now, we're taking a look at New Yorkers' ancestral backgrounds.

The American Community Survey is a massive annual effort by the Census Bureau to understand the citizens of the United States. Over three million people per year are asked questions about housing, demographics, and economics.

In one of the many questions on the ACS, respondents are asked to identify their ancestry. This is a very open-ended question, and the Census Bureau provides numerous options. Here are the most common ancestries in each NYC neighborhood:

Business Insider/Andy Kiersz, data from 2012 American Community Survey PUMS

The map was made using the ACS Public Use Microdata Sample, an edited version of the individual responses to the survey. With this data, we were able to calculate the most common ancestry in each of New York City's Census-designated "Public Use Microdata Areas," which closely conform to the city government's community districts, for which the city provides very nice-looking map outlines.