Love clams and chowder? Everyone’s heard of clam chowder, but did you know that it’s also has a holiday? National Clam Chowder Day is a day all about celebrating the history of this beloved fish stew, historical in its origins to the New England area and helped ultimately inspire creations such as the Manhatten clam chowder, Rhode Island clam chowder, and Long Island clam chowder.