We can triangulate this pretty well, then; I am 51 and had a Girl Scout handbook with a recipe for peanut butter and jelly sandwiches that did not include butter.
I have The American Woman's Cookbook, dated 1946, with clear and emphatic instructions at the beginning of the sandwich section that all sandwiches must begin with spreading butter meticulously from edge to edge of the bread, explicitly to keep the bread dry.
no subject
no subject
no subject
no subject
no subject
no subject
no subject