The purpose of separation of church and state is to keep forever from these shores the ceaseless strife that has soaked the soil of Europe in blood for centuries.

Though this had been cited as being from a letter objecting to the use of government land for churches in 1803, as quoted in 2000 Years of Disbelief: Famous People With the Courage to Doubt (1996) edited by James A Haught, no original source for this has yet been found.