Chowder, in North American cuisine, is a hearty soup usually containing fish or shellfish, especially clams. The word chowder is a corruption of the French chaudière (“cauldron”), and chowder may have originated among Breton fishermen who brought the custom to Newfoundland, whence it spread to Nova Scotia, New Brunswick, and New England. The standard New England-style chowder contains fish or shellfish, salt pork, onions, potatoes, and milk.

Source: Britannica