In 1754 he obtained a certificate enabling him to pursue his work abroad, and immediately visited North America, where he remained till 1756, visiting nearly all the Quakers' meetings in the northern and many in the southern colonies.
On his return to England he organised a subscription for the relief of the poverty occasioned by the scarcity of employment round Warrington during the winter of 1756, and resumed his ministerial work until his incessant labours caused a severe illness.