La Fontaine was first elected to the
Legislative Assembly of Lower Canada in 1830. LaFontaine had been a member of the
Parti patriote and a supporter of
Louis-Joseph Papineau leading up to the Rebellion, but after the Rebellion failed he re-examined his political views. He decided to switch to a system of working within the existing constitutional order to achieve the political rights of French-Canadians. He adopted the cause of
responsible government, where the Governor General would appoint the members of the Executive Council from the groups which controlled a majority in the elected Legislative Assembly. Anticipating that he would stand for election in the riding of
Terrebonne, with a large majority population of French-Canadians, LaFontaine set out his new political approach in an
Address to the Electors of Terrebonne. At that time, it was not uncommon for there to be election violence. Voting was by open-ballot, where each voter publicly declared their vote at the poll. One common tactic was for the supporters of one candidate to try to control the poll and prevent the voters for the other candidate from voting. In the run-up to the Terrebonne election in March 1841, LaFontaine began to hear rumours that Sydenham and the supporters for the government candidate,
Michael McCulloch, planned to bring in large numbers of men from outside the riding to control the poll and prevent his supporters from voting. One of LaFontaine's supporters wrote to him and suggested that they could hold the poll, if he was able to organise one thousand men to support his position. One of the English-language newspapers in Montreal expressly stated that the goal was to prevent French-Canadians from voting in the poll: The poll was located at
New Glasgow, one of the few towns in the riding with an English-speaking majority, and located on the outskirts of the riding, away from the major population centres. The day of the election, LaFontaine led a group of his supporters in a march to New Glasgow, where they would vote. Fearing violence, many of them were armed with clubs and pitchforks, which was not uncommon in contested elections. As they neared New Glasgow, they found the road blocked by groups of men supporting McCulloch, perhaps six or seven hundred in total. They too were armed, many with clubs, but some with firearms. Small fights began to break out, and there was blood on the snow. LaFontaine, fearing for the safety of his supporters, abandoned the march to New Glasgow. Since only McCulloch's supporters voted for him, the returning officer declared McCulloch the elected candidate. At first, LaFontaine thought there was no point in continuing in politics and announced his retirement from public life. But then a surprising event occurred.
Robert Baldwin, a leading Reformer in Canada West, contacted LaFontaine. Following the elections in Canada West, there was a vacant seat, York 4th, where Baldwin had been elected as a Reformer but had resigned. Baldwin offered to nominate LaFontaine as the candidate for the riding in the upcoming
by-election, with the support of the local Reform party members. Before making the offer to LaFontaine, Baldwin had obtained the agreement of
David Willson, leader of the
Children of Peace, a Quaker religious group that was made up of strong Reformers, and Willson had agreed. LaFontaine gratefully accepted the offer, and with the support of Baldwin and the local Reformers, was elected in the by-election. The concept of a French-Canadian winning a seat in Canada West was remarkable. It was a strong indicator to French-Canadians that they had allies in their quest for popular control of the provincial government. A leading French-Canadian journalist and political writer, Étienne Parent, had accompanied LaFontaine to Canada West and reported back on their reception by West Canada reformers: "Ils élisent M. Lafontaine pour montrer, disent-ils, leur sympathie envers les Bas-Canadiens, et leur détestation des mauvais traitements et des injustices auxquelles nous avons été exposés." The episode was the beginning of the alliance between reformers in Canada East and Canada West that LaFontaine had argued for in his
Address to the Electors. Baldwin also insisted that Sydenham include La Fontaine in the reformed Executive Council, or he would resign as Solicitor General. Their alliance allowed La Fontaine to have a seat in the assembly in 1841 and for Baldwin to win the by-election in 1843. During the 1840s, Willson continued his association with the Reform Party; he was, for example, the campaign manager in the area for both
Robert Baldwin and LaFontaine, the "Fathers of
Responsible Government" and first elected premiers of the province. It was the Children of Peace who ensured the election of Montreal lawyer Louis La Fontaine as their representative in Upper Canada. Willson argued that this was an opportunity, as he said, "to show our impartial respect to the Canadian people of the Lower province." Here, Willson is expressing a clear Canadian identity that overcame differences in the language and religion. It was a vision of Canadian citizenship that was ultimately successful, as La Fontaine was elected in the 4th Riding of York. Subsequently, they elected Baldwin in their riding. The band of the Children of Peace was a familiar sight at Baldwin's campaign rallies. In 1844, they held a campaign rally for Baldwin concurrently with the illumination of the Temple. Over 3000 people attended, an event that helped end the reign of Orange Order electoral violence. On 3 September 1841, the Children of Peace held a campaign rally for Baldwin and La Fontaine in their
Temple, where they rejoiced "to say that we have it in our power to show our impartial respect to the Canadian people of the Lower Province." Despite threats of Orange Order violence, La Fontaine was
elected as representative of 4th York. However, before La Fontaine could take up his seat, Governor Sydenham died. His replacement, Sir
Charles Bagot, was not able to form a mixed cabinet of Reformers and Tories, and so he was forced to include the "Canadien party" under La Fontaine. La Fontaine refused to join the Executive Council unless Baldwin was also included. Bagot was finally forced to accede in September, 1842, and when he became severely ill thereafter, Baldwin and La Fontaine became the first real premiers of the Province of Canada.{{cite book|last=Saul|first=John Ralston|author-link=John Ralston Saul ==Later life and death==