These are called "Alley Houses". They are built directly behind the homes you saw in the first picture.... as an after thought.
This is the new Congressional Overlook. I did find the starting price to be $850,000 and up to $1,299,900. If you are interested you can check out the website at http://www.congressionaloverlook.com/#2 . Just a short walk to the capitol!!!!! Oh yeah, I could live here for sure!