Don't forget the Cowboy breakfast of the American West. The original Hobbit two breakfasts...

First breakfast: Coffee and toast, biscuits, or a hunk of bread. Had just before first light, on the way out to tend the animals.

Second breakfast: Steak (or thick cut ham) and eggs, potatoes, biscuits (often with gravy), baked beans, lots of strong coffee.

Second breakfast out on the range: Baked beans with ham/bacon cooked in, biscuits and gravy/butter, lots of strong coffee.

Should also be mentioned that in Britain, the idea of a 'full breakfast' was only available to those with money. Poor people sustained themselves on porridge or some form of bread. In Ireland, it would have meant potatoes until Famine times, then porridge oats but never in great supply.