The 1887 and later Hopkins atlases are offline currently (they are not available through Library of Congress--which has the Baist atlases).
There is new Dig DC! All the collections you know and love will be available soon; please bear with us as we migrate them. In the meantime, if you're looking for a photograph, oral history, map, or newspaper that isn't here yet, please email us at firstname.lastname@example.org.
There is an alternative for the 1887 (and 1894 v.3) Hopkins atlas--DCRA's Surdocs system: