 In 1864, when no party proved capable of governing for long, Macdonald agreed to a proposal from his political rival, George Brown, that the parties unite in a Great Coalition to seek federation and political reform.Macdonald was the leading figure in the subsequent discussions and conferences, which resulted in the British North America Act, 1867 and the birth of Canada as a nation on 1 July 1867.Macdonald was the first Prime Minister of the new nation, and served 19 years; only William Lyon Mackenzie King served longer.