Founder of the Quakers, George Fox was imprisoned here for non-conformity between April and July 1655. William Penn first stayed in the town on 1st October 1672 during his missionary ‘Journey on Truth’s Account Through Kent, Sussex and the Skirt of Surrey’. He attended the Quaker Horsham Men’s Monthly Meeting at least four times in the 1670s-80s and his Declaration to marry second wife Hannah Callowhill was heard before them on 11th December 1695. Penn’s daughter Letitia made her Declaration to marry William Aubrey, a London merchant, before the same body 0n 8th July 1702 and the Horsham Women’s Monthly Meeting were given a letter about the same.

Horsham General Baptist Chapel (now Horsham Unitarian Church) was founded in [1719] and served as the meeting place for the large number of General Baptist families in Horsham and the surrounding area; this was partly due to the influence of the radical preacher and writer Matthew Caffyn (1628-1714) who was born and lived in Horsham. A number of members of the Horsham General Baptist meeting emigrated to the United States in [1794]; their correspondence back home, particularly with James and John Browne comprises much of the content of the Browne family letter books (Add Mss 29203-29204).