Going by first use by the term, poundcake would be British by about 30 years prior to the influential book American cookery (https://en.wikipedia.org/wiki/Ameri

Going by first use by the term, poundcake would be British by about 30 years prior to the influential book American cookery (https://en.wikipedia.org/wiki/American_Cookery https://en.wikipedia.org/wiki/American_Cookery). But modern poundcake also relies on the american invention of "double acting baking powder".