In 1907–09, the church installed stained-glass windows by the noted J&R Lamb Studios. This studio opened it doors in 1857 and is now the oldest existing studio of its kind in the US. The windows in Plymouth Church are unique in that they do not depict any biblical scenes. Instead they focus on the history of democracy in England and the US, with a particular emphasis on the influence of the Puritans, Pilgrims and Congregational Churches. In 1913 the family of John Arbuckle, a coffee merchant, donated money to create a large garden and the Classic revival parish house. The house and arcade which adjoin the building were designed by Woodruff Leeming.