His wife had already been made a minister in 1810, and shortly afterward he began sitting on Quaker committees; in 1817 he became an elder of the church.

[3] In 1838, Forster accompanied Elizabeth Fry, her husband, Lydia Irving and William Allen on Friend's business and a tour and inspection of prisons in France.

The controversy was named after a book published in January 1835 called A Beacon to the Society of Friends[6] which was written by Isaac Crewdson, a leader to the Manchester Quaker meeting.

The controversy, which related to evangelism in the society, eventually led to the resignation of Crewdson and about 300 similarly minded people across the country.

A picture was commissioned that showed the delegates, including Josiah Forster, of the new British and Foreign Anti-Slavery Society which was formed in 1839.

[1] Also in this painting are Josiah's brothers, Robert and William Forster, many significant figures including Isaac Crewdson.

The difference developed over the ways that the society should support slavery, which was still an important part of the American economy.

It was during this journey that William died and was buried in the Quaker town of Friendsville in Tennessee which was on the Underground Railroad.

[12] Josiah Forster and his wife, Sarah, established a trust in 1862, where four new cottages were to be given to poor widows aged 55 or over.