The data comes from here:

https://factfinder.census.gov/faces/tableservices/jsf/pages/productview.xhtml?pid=ACS_15_5YR_S2401&prodType=table


I only edited the header variables at the top slightly:
Replaced "GEO.id" with "id"
Replaced "GEO.id2" with "id2"
Replaced "GEO.display-label" with "name"

The example uses the p5 dom library. It allows you to create html elements, not only draw onto the html canvas. See more info here:
https://github.com/processing/p5.js/wiki/Beyond-the-canvas