How did egg-centric dishes become "breakfast only" food in American cuisine? [closed]

Eggs are great.

You see eggs in lots of dishes in American cuisine. Egg salad made from hard-boiled eggs is an American cookout standard. Fried eggs often go on burgers; poached eggs frequently find themselves atop sandwiches and salads. Scotch eggs are a frequent side dish or appetizer. But in American cuisine, eggs are almost never the focal point of a dish.

Except at breakfast.

Omelettes, scrambled eggs, and quiches abound at breakfast and brunch.

At what point in history did eggs become a "breakfast-only" main dish?