I have "Teaching Truth, Training Hearts: The Study of Catechisms in Baptist Life" by Dr. Tom Nettles. In it he states the original Baptist Catechism (a baptised verison of the WSC) was originally used in England. It was later modified by Spurgeon (Spurgeon's Puritan Catechism). It was revised in America and used by the Philadelphia Association (Keach's Catechism). The Charleston Association left it untouched (The Baptist Catechism of the Charleston Association) as evidenced by comparing it with Benjamin Beddome's "A Scriptural Exposition of the Baptist Catechism".