A couple of places to try for Newport, Rhode island are: http://www.newportmansions.org http://www.gonewport.com/

For a list of the mansions in the Hudson River Valley: http://www.hvnet.com/

If you're heading farther north (to the Adirondacks), check out: http://tinyurl.com/ipba

Regards, Al Sonoma, CA, USA