Complex sentence: Hamilton led the Progressive Conservative Party of Saskatchewan from 1949 until he was elected to the Canadian House of Commons in the 1957 general election that brought the federal Progressive Conservatives to power under John George Diefenbaker.
Split into simpler sentences: Hamilton led the Progressive Conservative Party of Saskatchewan from 1949 until he was elected to the Canadian House of Commons in the 1957 general election. This election brought the federal Progressive Conservatives to power under John George Diefenbaker.