Ask HN: Housing history of area by zipcode (overtime)?

National Association of Realtors has this information readily available. That said, you must become a realtor and associate yourself with a brokerage in order to access it.

I am not sure of a specific site that would include all data, but an avenue you may explore is government open data or scraping tax records for each state. For example, in Maryland you can search the property records for every house. It will show you all sales, name/purchase price, since the property was built. I am not sure if there is an API or what their terms are specifically. I do know other states offer similar services as well. Some offer it statewide, and others have county specific sites (i.e. in Delaware each county has their own website with the records).

The Maryland site is: http://sdat.resiusa.org/RealProperty/Pages/default.aspx

Not sure if that helps or not :)

EDIT: I found this site, which seems useful for this use: https://www.quandl.com/

Thanks for mentioning Quandl, @a_lifters_life!

As someone who works at Quandl, I wanted to point out that we do have some free real estate data:

The Zillow database shows home prices and rents by size, type and tier, housing supply, demand and sales etc: https://www.quandl.com/data/ZILL

The National Association of Realtors database shows average and median home prices by area and dwelling type: https://www.quandl.com/data/NAR

The Freddie Mac database shows house price indexes for various American cities as well as historical mortgage rates: https://www.quandl.com/data/FMAC

Hope this helps! I don't believe these show house prices by zip code, but they are divided by area.