Vintage Color Chrome Postcard. "Greetings from Calais, Maine." Published by Dexter Press. Divided back, unused. Condition: Very Good. Comments: Calais is a city in Washington County, Maine. As of the 2010 census, it had a population of 3,123. The city has three United States border crossings over the St. Croix River bordering St. Stephen, New Brunswick, Canada. Calais has historically been a city of commerce and is recognized as the primary shopping center of eastern Washington County and of Charlotte County, New Brunswick. Currently retail, service, and construction businesses are the primary components of the Calais economy.