The small stone house was once the home of the lockkeeper for this branch of the C&O Canal. Lock B once stood at what is now the intersection of 17th Street and Constitution Avenue. Boats would arrive at the lock, pay a toll to the lockkeeper, wait for the water levels to be adjusted and then travel from the B Street Canal to the City Canal or vice versa.
It's not clear when the lockkeeper's house was built, but the National Park Service certifies that it was in existence by 1833.
Chesapeake and Ohio Canal Lockkeeper