Ruth Watkins itinerated as a Primitive Methodist preacher in the extensive Tunstall circuit from 1825-1829. Accounts of her work come from as far afield as Dorset and several of her converts became travelling preachers. There are extracts from her Journals in the Primitive Methodist Magazine.
In 1829 the PM Conference decided that, as many Primitive Methodists had emigrated to America, a mission should be sent there. Ruth was nominated with William Knowles, Thomas Morris and William Summersides. They sailed from Liverpool on 19th June 1829, arriving in New York on Friday, 31th July. Ruth sent back reports of her experiences and impressions in the Primitive Methodist Magazine. The change of climate and environment affected her health. Ruth worked in New York and the Philadelphia, studying, visiting, leading classes, week-long prayer meetings and love-feasts, opening new stations and preaching, indoors and outside, often up to three times a day. In 1831 she was joined in Philadelphia by her brother Nathaniel and his wife. The same year Ruth was asked to open new missions (often assumed to be in Canada) and did so around Albany and Troy, but her health gave way and she retired in 1832. She was reported to have married an Episcopalian minister in 1831, but she makes no mention of this. Ruth wrote to William Clowes in 1835 expressing her disillusionment with Primitive Methodism in North America.