It all comes down to the cream! New England Clam Chowder is made with milk and/or cream so it comes out thick and creamy. Rhode Island Clam Chowder is essentially exactly the same as its New England counterpart but it's made without dairy so it comes out with a clear broth. Manhattan Clam Chowder (or red clam chowder!) omits dairy and is made with more tomatoes and veggies!