Complex sentence: During the 1830s, the diet had a moderate response from the mostly puritanical faction of the American public, so much so that at one point it was strictly imposed on students of Oberlin College by David Campbell (a disciple of Graham's).
Split into simpler sentences: During the 1830s, the diet had a moderate response, mostly from the puritanical faction of the American public. At one point it was strictly imposed on students of Oberlin College by David Campbell (a disciple of Graham's).