I submit that the division between English and American pancakes is not a Shift but a Schism. The parallels are everywhere: like Christianity, pancakes are ancient; like Christianity, written recipes for pancakes are first attested in late antiquity; like Christianity, pancakes are found in myriad acculturated forms throughout the world; and like Western and Eastern Christianity in 1054, the great division between American and British pancakes involved an irreconcilable difference of opinion over leavening.

The basic pancake recipe in both countries involves flour and liquid, typically milk and eggs. Alcohol--beer or brandy--or snow might be substituted in the absence of available eggs, plus butter, sweetener, or spices might be added to preference. Buttermilk or cream were additional substitutions/inclusions. But American traditional pancakes include an extra ingredient: a chemical leavener (that is, baking powder or baking soda).

These first came to market in the late 18th century, and were affordable in America by the mid-19th. It was readily adopted into griddle-cake cooking, perhaps with some nod to the puffy Pfannkuchen of German-Dutch cooking. The Great Pancake Schism had wrenched apart the two pancake cultures by 1860, when an article on New York cuisine in the London Times reported:

Hot cakes are an American institution (every custom, I should remark, is termed an “institution” in America). These hot cakes resemble crumpets, and are generally served in a pyramidal form, a large cake forming the base, and the small one the apex of the pile.

Our intrepid traveler further confirms the use of molasses-style syrup and butter to complete the traditional American pancake stack!

By the late 19th century, Aunt Jemima pancake mix (which predated the syrup, in fact) was all the rage in ready-made meal supplies. With the leavening already mixed in, the American commitment to fluffy pancakes had become automatic.