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.
Homes - Famous, Canals
It's not clear when the lockkeeper's house was built, but the National Park Service certifies that it was in existence by 1833.