They were similar to continental breakfasts, with coffee and bread. Oatmeal was still pretty big in the north, while grits were the thing in the south. Orange juice was pretty commercialized at the time, so a wealthy family would have likely had orange juice. Bacon and Eggs were also a pretty normal meal at the time for breakfast, so they might have had that as well. Dry cereal also started to be more commercialized. Breakfast hasn't really changed too much since the 1920's. There's some mention of breakfast here (http://www.foodtimeline.org/fooddecades.html#1920s), but it focuses mostly on a lot of other foods.