John Adams wrote in 1795, with some exaggeration and incoherence: "Argument might have [had] some weight in the abolition of slavery in Massachusetts, but the real cause was the multiplication of labouring white people, who would no longer suffer the rich to employ these sable rivals so much to their injury ...

If the gentlemen had been permitted by law to hold slaves, the common white people would have put the negroes to death, and their masters too, perhaps ...
The common white people, or rather the labouring people, were the cause of rendering negroes unprofitable servants.

Their scoffs and insults, their continual insinuations, filled the negroes with discontent, made them lazy, idle, proud, vicious, and at length wholly useless to their masters, to such a degree that the abolition of slavery became a measure of economy."[10] [Footnote 10: Massachusetts Historical Society _Collections_, XLIII, 402.] Slavery in the rest of the Northern states was as a rule not abolished, but rather put in process of gradual extinction by legislation of a peculiar sort enacted in response to agitations characteristic of the times.
Pennsylvania set the pattern in an act of 1780 providing that all children born thereafter of slave mothers in the state were to be the servants of their mothers' owners until reaching twenty-eight years of age, and then to become free.

Connecticut followed in 1784 with an act of similar purport but with a specification of twenty-five years, afterward reduced to twenty-one, as the age for freedom; and in 1840 she abolished her remnant of slavery outright.

In Rhode Island an act of the same year, 1784, enacted that the children thereafter born of slave mothers were to be free at the ages of twenty-one for males and eighteen for females, and that these children were meanwhile to be supported and instructed at public expense; but an amendment of the following year transferred to the mothers' owners the burden of supporting the children, and ignored the matter of their education.