Complex sentence: Dunning left provincial politics in 1926 to join the federal Cabinet of Prime Minister William Lyon Mackenzie King serving as minister of railways and canals and then minister of finance in the King governments of 1926-30 and 1935-39.
Split into simpler sentences: Dunning left provincial politics in 1926 to join the federal Cabinet of Prime Minister William Lyon Mackenzie King. He served as Minister of Railways and Canals and later as Minister of Finance in the King governments of 1926-30 and 1935-39.