Fold3, formerly Footnote, has an impressive digital collection of documents related to captured documents and archives from World War II. See especially, sections on
WWII Captured German Records, various Ardelia Hall Collections (such as the
Offenbach Administrative Records) and the Office of Military Government U.S. (OMGUS) Cultural Affairs Branch, which includes a wide variety of records related to
Archives in WWII. Certain of these collections used to be available online for free, but now unfortunately require membership.
