It's too hot to hold a consistent thought, and my next post from Oregon requires a bit of research, so let's jump around!
Cobblestone houses aren't too common. It is believed that about 700 of them were built in the 1800s. Almost all of them are located near Rochester, New York. That area had the two main ingredients: raw materials (cobblestones from Lake Ontario or glacial deposits and plenty of limestone for mortar) and labor (English masons that immigrated to work on the Erie Canal) for constructing such buildings.
The building above is the Livingston County Museum in Geneseo. It was built in 1838 as a schoolhouse and was given to the county in 1932.