This data set corresponds to the adjusted same-sex couples counts from the 2010 American Community Survey.
Sources:
http://www.nytimes.com/2015/06/27/upshot/supreme-court-gay-marriage-ruling-where-same-sex-couples-li...
http://williamsinstitute.law.ucla.edu/headlines/gary-gates-discusses-newly-released-census-data-on-s...
The data set is discussed in my JMP blog post on this topic.