Robert Long House (39.282223 -76.591362)
According to Fedor's guide (http://www.fodors.com/world/north-america/usa/maryland/baltimore/things-to-do/sights/reviews/robert-long-house-museum-166973/) the Robert Long House is the "city's oldest residence still standing. This small brick house was built in 1765 as both home and business office for Robert Long, a merchant and quartermaster for the Continental Navy who operated a wharf on the waterfront. Furnished with Revolutionary War–era pieces, the parlor, bedroom, and office seem as if Long himself just stepped away. A fragrant, flowering herb garden flourishes in warm months."
For a recent effort at telling the history of the house and its residents prior to 1845, see Recreating Lost Neighborhoods: The House on Ann Street, Fells Point, Baltimore City, Maryland