Native American seed stock, particularly potato and corn, changed the diet of Europe. Both crops produce far more calories per acre than wheat; the potato will grow in poor soils and in a wide variety of environments, from sea level to ten thousand feet. Corn is more fastidious, requiring rich soil and long stretches of hot weather, but it can grow in “in-between” climates too dry for rice but too wet for wheat. An impoverished swath of southern Europe stretching from Portugal to the Ukraine filled this bill precisely. By 1800 it had become one of the world’s largest corn growing regions.
