Complex sentence: He held the Nelson electorate for one parliament, from 1914 to 1919, after defeating Harry Atmore in 1914, but Atmore won the seat back in 1919, and held it for 27 more years.
Split into simpler sentences: He held the Nelson electorate for one parliament, from 1914 to 1919, after defeating Harry Atmore in 1914. But Atmore won the seat back in 1919, and held it for 27 more years.