Complex sentence: He opposed the protectionist tariff bills of 1824,1828, and 1832, and consistently upheld the doctrine that slavery was a domestic institution and should be dealt with only by the individual states.
Split into simpler sentences: He opposed the protectionist tariff bills of 1824,1828, and 1832. He consistently upheld the doctrine that slavery was a domestic institution and should be dealt with only by the individual states.