You think the rivalry between Manhattan clam chowder and New England clam chowder (sometimes called Boston clam chowder) isn't as serious as YankeesRed Sox or Rangers-Bruins? Consider this: in 1939, a bill was introduced in the Maine legislature to make it illegal to add tomatoes to chowder. For decades, New Englanders have viewed tomatoes in clam chowder as an affront to the very essence of soup. Chowder, New England adherents believe, should be thick, creamy and cream-colored, and that version has been around since at least the 1830s. But leave it to New Yorkers to reinvent something and call it their own. In the mid-1800s, the large Italian population in New York started using tomatoes in their chowder, thinning it out and giving it a reddish color, and hence, a new chowder was born. But we think if you surveyed even Manhattanites on the superior chowder, they'd clam up and go with New England's.