The house that is referred to in this photo on "N Street" is located at 3033 N Street NW. It is one of the oldest houses in DC. It's called the George Beall House. George Beall owned all the land that became Georgetown.

Sarah Nixon's family owned it. Robert Nixon registered his Earth Conservation Corps using this address.

https://clustrmaps.com/a/22jtba/

https://en.wikipedia.org/wiki/George_Beall

https://georgetownmetropolitan.com/2010/11/18/the-story-of-how-georgetown-found-it-grid/