This was initially as assistant to Rev Dr James Morgan, but from 1873 he became minister in charge.
[4] In 1896 he succeeded Rev George Raphael Buick as Moderator of the General Assembly.
A stained glass window in Fisherwick Church is dedicated to his memory.
Their son James Robert David Williamson (1856-1891) also became a Free Church minister.
[6] His son Charles Frederick Williamson (1868-1915) married a nurse, Edith Nugent, and they moved to India.