The discipline of the Quakers was therefore a school for bringing them up as advocates for the abolition of this trade.

To this it may be added, that the Quakers knew more about the trade and the slavery of the Africans, than any other religious body of men, who had not been in the land of their sufferings.
For there had been a correspondence between the society in America and that in England on the subject, the contents of which must have been known to the members of each.

American ministers also were frequently crossing the Atlantic on religious missions to England.

These, when they travelled through various parts of our island, frequently related to the Quaker families in their way the cruelties they had seen and heard of in their own country.

English ministers were also frequently going over to America on the same religious errand.