Dorion was born in Ste-Anne-de-la-Pérade into a family with liberal values that had been sympathetic to the Patriotes in 1837-1838. His father, merchant Pierre-Antoine Dorion, was a representative of the Patriote party in the Legislative Assembly of Lower Canada from 1830 to 1838. After studies at the Nicolet seminary from 1830 to 1837, in his twenty-second year went to Montreal to read law with Côme-Séraphin Cherrier, an eminent lawyer for whom he retained a lasting friendship. On the 6th of January 1842 he was admitted to the bar of the province, became the partner of M. Cherrier, and in the course of a few years attained the highest rank in his profession.
Political rise
Dorion descended from a Liberal family which from early days had supported the Reform party in Canada. In addition to his father, his maternal grandfather represented the county of Saint Maurice in the Legislative Assembly from 1819 to 1830. At the time that Dorion commenced the study of law, Canada was entering a struggle between Lower Canada and Upper Canada for a balance of representation. Although a decisive political victory had been gained, and a responsible government formed, by Louis-Hippolyte Lafontaine and Robert Baldwin in 1848, they did not press for an immediate overthrow of existing institutions, and in 1851, the administration was handed over to Francis Hincks and Augustin-Norbert Morin. The elections of 1854 had brought new reformist blood into the ranks of the Liberal party. Dorion was elected as member of the assembly for the province of Canada for the city of Montreal, and was chosen as leader. It seemed that the coalition government under Allan MacNab had clarified the situation, but by 1856 Upper Canada had increased, and it contributed a larger share to the revenue, and demanded proportionate representation. Dorion understood the true principle of federation as applicable to Canada, but he did not pursue this idea, and in fact his following was never sufficiently strong to enable him to give effect to the sound measures he was so capable of formulating.
Government
In 1858 Dorion served as Co-Premier of the Province of Canada with Clear Grit leader George Brown but the government fell within three days. From 1863 to 1864 Dorion again served as Co-Premier, this time with John Sandfield Macdonald as well as taking the position of Attorney-General, but refused to participate in the Great Coalition government formed in 1864 by Brown, John A. Macdonald and George-Étienne Cartier. Following the Quebec Conference of 1864 he denounced the proposed Canadian Confederation and led the opposition in Lower Canada to the project. He was also the leader of the Parti Rouge and thought the provinces would lose their power if Confederation was put into action. He disapproved that the colonies of New Brunswick, Nova Scotia, and Prince Edward Island were uniting under a central government. Dorion expressed his rejection of confederation through a manifesto in 1864, multiple articles from 1865 to 1867, and his attendance of opposition meetings in Lower Canada.
