I want to know the answer to the following question:
Who promoted strict immersion baptism?
All the background I'm provided with is that "According to Tom Nettles, professor of historical theology at Southern Baptist Theological Seminary, "Spilsbury's cogent arguments for a gathered, disciplined congregation of believers baptized by immersion as constituting the New Testament church gave expression to and built on insights that had emerged within separatism, advanced in the life of John Smyth and the suffering congregation of Thomas Helwys, and matured in Particular Baptists."". Is that enough to answer the question?
Answer: no