usually the images are like "last rites" before a
structure or place is removed or altered completely.
typically, unless the government is doing this sort of thing to a "national treasure"
-- like in pawtucket rhode island several years ago there was a habs recordation
of the slater mill, the birthplace of the american industrial revolution ...
unlike the documentation of the mill, which was a not because the owners
wanted to do anything diverse with the propert ( it's a museum )
most documentations are a "requirement" that the developer or property
owner has to do.
i think you might be able to search
parts of the collection here: http://lcweb2.loc.gov/pp/hhquery.html