Complex sentence: William Pitt the Younger attempted to get the idea passed into legislation but failed, the system was not a national system but was popular in the counties which experienced the Swing Riots during the 1830s.
Split into simpler sentences: William Pitt the Younger attempted to get the idea passed into legislation but failed. The system was not adopted nationally but was popular in the counties which experienced the Swing Riots during the 1830s.