Colonial adultery laws

Here is what domestic crimes used to be:

Vermont's adultery law, 1779, is like CT's. It reads: "whosoever shall commit adultery with a married woman, or one betrothed to another man, both of them shall be severely punished by whipping on the naked body not exceeding thirty-nine stripes, and stigmatized, or burnt on the forehead with the letter A, on a hot iron; and each of them shall wear shall wear the capital letter A, on the back of their outside garment, of a different colour, in fair view, during their abode in this state. And as often as such convicted person shall be seen without such letter, and be thereof convicted before an assistant or justice of the peace in this state, shall be whipped on the naked body, not exceeding ten stripes." Laws of Vermont, 1777-1780, ed. Allen Soule, vol. 12 of State Papers of Vermont (Montpelier: Secretary of State, 1964), 38.

Note that adultery has been defined by the woman being married. That is how it has always been defined, until recently. Non-marital sexual intercourse by a woman is a much greater offense, because of the possibility of a child with the wrong father.