In North America Chowder is a generic name for a wide variety of seafood or vegetable stews and thickened soups, often with milk or cream

Cream

Cream is a dairy product that is composed of the higher-butterfat layer skimmed from the top of milk before homogenization. In un-homogenized milk, over time, the lighter fat rises to the top. In the industrial production of cream this process is accelerated by using centrifuges called "separators"...

. Some varieties are traditionally thickened with crushed ship biscuit

Hardtack

Hardtack is a simple type of cracker or biscuit, made from flour, water, and sometimes salt. Inexpensive and long-lasting, it was and is used for sustenance in the absence of perishable foods, commonly during long sea voyages and military campaigns. The name derives from the British sailor slang...

 instead of flour, which is more usual. New England clam chowder - perhaps the best known chowder - is typically made with chopped clam

Clam

The word "clam" can be applied to freshwater mussels, and other freshwater bivalves, as well as marine bivalves.In the United States, "clam" can be used in several different ways: one, as a general term covering all bivalve molluscs...

s and diced potatoes, in a mixed cream and milk base, often with a small amount of butter.