Complex sentence: Oliver was re-elected as a UFO MPP in 1929 and was the sole (and last) United Farmers member in the legislture until 1940 when he joined the Ontario Liberal Party and the cabinet of Premier Mitchell Hepburn as Minister of Public Works and Welfare.
Split into simpler sentences: Oliver was re-elected as a UFO MPP in 1929 and was the sole (and last) United Farmers member in the legislature until 1940. In that year, joined the Ontario Liberal Party and the cabinet of Premier Mitchell Hepburn as Minister of Public Works and Welfare.