I am looking for time series data for property values in the Cambridgeport 
neighborhood in Cambridge, MA. I would like a website where I can look
at some houses in the neighborhood and see how their selling prices
have changed over the years. In other words, for at least 10 houses,
I'd like to see how their selling prices have changed over the years
as they have been sold several times. The data should go back at least
20 years, but I'm really hoping to get data that goes back farther.

Thank you

Hi,
You will love zillow.com!  It can do just what you want for the last
ten years, at least it appears to.  Going further back than that,
well, I hope a Researcher can tell you if the information for
individual houses is available on the county recorder's website.