"In the eighteenth and early nineteenth centuries, recipes for making soy sauce at home appeared in English and American cookbooks. Since soybeans were not widely available, these recipes used local ingredients such as mushrooms, walnuts, and fish...

Tomato was another popular ingredient for making American "soy" sauce... The names for these varying sauces were "ketchups," or "catch-ups," or "catsups," derived from the Indonesian word for soy sauce: ketjap."

-- "Eight Flavors"

ketchup is soy sauce????????????????