Judging from the cars in the picture this card is probably from the late 1930s.
Caption on back:
     Allen County Memorial Hall was built as a memorial to Civil War Veterans.
It contains a large auditorium, seating 1600 persons, is the G. A. R., American
Legion, and Veterans of Foreign Wars headquarters. The second floor houses
the Allen County Historical Society's collection, which is highly valuable in historic
interest.