In process of time he began to bear his testimony against it, by representing the unlawfulness of it to those of his own Society, when assembled at one of their yearly meetings.

This expression of his public testimony, he continued annually on the same occasion.

He wrote also several Tracts with the same design, one of which, published in the year 1718, he addressed to the elders of his own church, on the inconsistency of compelling people and their posterity to serve them continually and arbitrarily, and without any proper recompense for their services.
The next was Ralph Sandiford, a merchant in Philadelphia.

This worthy person had many offers of pecuniary assistance, which would have advanced him in life, but he declined them all because they came from persons who had acquired their independence by the oppression of their slaves.

He was very earnest in endeavouring to prevail upon his friends, both, in and out of the society, to liberate those whom they held in bondage.