In the year 1760, he travelled, in company with his friend Samuel Eastburne, to Rhode Island, to promote the same object.  This island had been long noted for its trade to Africa for slaves.  He found at Newport, the great sea-port town belonging to it, that a number of them had been lately imported.  He felt his mind deeply impressed on this account.  He was almost overpowered in consequence of it, and became ill.  He thought once of promoting a petition to the legislature, to discourage all such importations in future.  He then thought of going and speaking to the House of Assembly, which was then sitting; but he was discouraged from both these proceedings.  He held, however, a conference with many of his own Society in the meeting-house-chamber, where the subject of his visit was discussed on both sides, with a calm and peaceable spirit.  Many of those present manifested the concern they felt at their former practices, and others a desire of taking suitable care of their slaves at their decease.  From Newport he proceeded to Nantucket; but observing the members of the Society there to have few or no slaves, he exhorted them to persevere in abstaining from the use of them, and returned home.

In the year 1761, he visited several families in Pennsylvania, and, in about three months afterwards, others about Shrewsbury and Squan in New Jersey.  On his return he added a second part to the treatise before published on the keeping of slaves, a care which had been growing upon him for some years.

In the year 1762, he printed, published, and distributed this treatise.

In 1767, he went on foot to the western shores of the same province on a religious visit.  After having crossed the Susquehanna, his old feelings returned to him; for coming amongst people living in outward ease and greatness, chiefly on the labour of slaves, his heart was much affected, and he waited with humble resignation, to learn how he should further perform his duty to this injured people.  The travelling on foot, though it was agreeable to the state of his mind, he describes to have been wearisome to his body.  He felt himself weakly at times, in consequence of it, but yet continued to travel on.  At one of the quarterly meetings of the Society, being in great sorrow and heaviness, and under deep exercise on account of the miseries of the poor Africans, he expressed himself freely to those present, who held them in bondage.  He expatiated on the tenderness and loving-kindness of the apostles, as manifested in labours, perils, and sufferings, towards the poor Gentiles, and contrasted their treatment of the Gentiles with it, whom he described in the persons of their slaves:  and was much satisfied with the result of his discourse.