So you want to eat breakfast like an American Colonist. Let's assume you're doing this is a school project or reenactment for your own personal amusement or enlightenment because the food the Colonists were eating wasn't great. This is no knock on the Colonists—I'm not trying to be like some time-traveling Gordon Ramsay just bellowing at these starving, scrappy people all, "I have found your biscuits tedious, your cornmeal quite drab, and your butter frowy!" They did the best they could with the often meager resources they had and tried to stay alive despite challenges of weather, scarcity, and storage. So maybe eating breakfast like a Colonist isn't a terrible exercise in experiential history.

On the frontier and farms, the day started early so people could maximize the daylight and get right to their often arduous tasks. This meant a hearty mug of beer or cider (yup, the alcoholic kind), plus some porridge that had been cooking down in the hearth overnight. In towns, the alcoholic brew was still standard fare, but might be served with cornmeal mush or pudding and molasses. There might be milk poured into the mush, and butter was something of a godsend.

Amelia Simmons, author of American Cookery, was touted on the title page as "an American orphan" but some scholars believe such a person may never have existed, and that this was a pseudonym. Still, the volume abounds with practical tips and recipes, such as this one for johnny cakes or hoe cakes—another breakfast staple.

Johnny Cakes or Hoe Cakes

Scald 1 pint of milk and put to 3 pints of Indian meal, and half pint of flour—bake before the fire. Or scald with milk two thirds of the Indian meal, or wet two thirds with boiling water, add salt, molasses and shortening, work up with cold water pretty stiff, and bake as above.

Indian meal was the Colonial term for cornmeal—a frequent component to breakfast, also referenced by author Mary Randolph in her 1831 The Virginia Housewife

To Randolph's sensibilities, "every woman of good sense and tolerable memory... must begin the day with an early breakfast, requiring each person to be in readiness to take their seats when the muffins, buckwheat cakes, &c. are placed on the table. This looks social and comfortable. When the family breakfast by detachments, the table remains a tedious time; the servants are kept from their morning's meal, and a complete derangement takes place in the whole business of the day. No work can be done till breakfast is finished." 

Servants. Yes. Presumably they, too, had families but Randolph doesn't pay them much heed. Rather more to the fancy folks of the Virginia colonies who were carbing up for the day ahead with mixed bread, sweet potato bread, and the crumpets of their not-long-ago homeland.

Mixed Bread

Put a teaspoonful of salt, and a large one of yeast, into a quart of flour; make it sufficiently soft, with corn meal gruel; when well risen, bake it in a mould. It is an excellent bread for breakfast. Indifferent flour will rise much better, when made with gruel, than with fair water.

Sweet Potato Buns

Boil and mash a potato, rub into it as much flour as will make it like bread--add spice and sugar to your taste, with a spoonful of yeast; when it has risen well, work in a piece of butter, bake it in small rolls, to be eaten hot with butter, either for breakfast or tea.

Crumpets

Take a quart of dough from your bread at a very early hour in the morning; break three fresh eggs, separating the yolks from the whites—whip them both to a froth, mix them with the dough, and add gradually milk-warm water, till you make a batter the thickness of buckwheat cakes: beat it well, and set it to rise till near breakfast time; have the griddle ready, pour on the batter to look quite round: they do not require turning.

 Recipes from American Cookery and The Virginia Housewife