Postcard above is not postally used. It depicts a busy street scene with a trolley and several pedestrians.   It is pre-linen with a white border, and  was published c.1920s by the Sabold-Herb Co., Philadelphia, PA.  The colors are very bright.  There is some scuffing on the divided back side, but no serious damage.  See larger view.

I have no connection to Delaware, but found these cards in an antique store in Atlanta and thought I'd share them.  They appear to be from the early 1920s.