Beech-Nut packing company.
Americans didn't start incorporating meat into breakfast consistently until the 1920's. A typical breakfast in the US prior to 1920's was fruit, a grain porridge and maybe a bread. Bacon suppliers like Beech-Nut wanted increased market demand for bacon so they started campaigning in the 1920s that Americans (mainly men) needed 'heavier' breakfast like bacon and eggs, it worked because so many men were still employed in manual labor jobs and you really only had two times a day to get your calories as lunch-breaks were much shorter. Eventually, in the end, large breakfast with consistent 'meat' became a staple for office men with 'leisure time' to eat a robust breakfast and a sign of wealth.
Most of what we see marketed back in the 50s isn't a real reflection of what was happening...most people couldn't afford meat like that and Sunday Dinner was popular and celebrated because it typically consisted of meat. Most of the marketing that went into Bacon and Sausage brands was from the POV of an office worker when most men, were in fact not office workers.
However, people are forgetting what the size of an average meal was back in the those days was; this 'hearty' breakfast was typically a fried egg or two and three rashes of bacon maybe a slice of toast with children often getting one egg and two rashes of bacon and no toast. People weren't eating Grits, Sausage, Eggs, Bacon, Hash-browns, Pancakes and toast in a singular breakfast sitting....These larger breakfasts we see today are a result of marketing and efficiencies/GMO created in the meat industry which has lowered the cost of meat and meat by-products to a level of affordability for consumers.