This is a fascinating interactive New York Times piece, showing where people in each state were born by census (from 2010, back to 1900).
As of 2010, 63% of New Yorkers were born in New York.
5% were born in Northeast states other than NY
3% were born in the South
2% were born in the Midwest
1% were born in the West
1% were born in other non-state parts of the United States (DC, Puerto Rico, the Virgin Islands, American Samoa, Guam, the Northern Mariana Islands)
24% were born outside the United States (up from 13% in 1970; down from 30% in 1910)
http://www.nytimes.com/interactive/2...abg=0#New_York