Postcard Washingtons Headquarters Plainfield NJ. Size: 3.5 x 5.5. Date: unknown. Publisher: The Collotype  CoPosted from: not posted. Posted to: not posted. Condition: one Very Good. No writing on the backs. Subject: Washingtons Headquarters Plainfield NJ.BUY TWO OR MORE FOR $3 EACH, JUST TELL ME WHICH postcards you WANT, AND WILL PUT IT AS A LOT IN A LISTING.