Complex sentence: Here he was conspicuous as an ardent free-trader and an uncompromising advocate of States Rights, opposed the protectionist tariff bills of 1824 and 1828, 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: Here he was considered a conspicuous ardent free-trader and an uncompromising advocate of States Rights. He opposed the protectionist tariff bills of 1824 and 1828, and consistently upheld the doctrine that slavery was a domestic institution and should be dealt with only by the individual states.