Throughout the nineteenth century, there was no one most popular religion for a length of time. The Christian denominations popular one decade would find themselves replaced by others in the next. This is echoed in our present century, as religions are always gaining and losing new members, with certain groups growing each year.
This century was full of religious revivals, including the Second Great Awakening. Traveling preachers often held camp meetings like the one in Huckleberry Finn. Church membership grew significantly.

19th Century Religion