Although it was centered on the town of Trois-Rivières, in the same way as the predecessor electoral district of the same name for Lower Canada, its boundaries had been significantly altered by the Governor General, Lord Sydenham, to favour voters of British background over the francophone Canadiens.

Sydenham wanted to ensure members were elected who would support the new union and his government and drew the boundaries with this goal.

The Act provided that the town would continue as a separate electoral district, electing one member to the Legislative Assembly.

[12] It was succeeded by electoral districts of the same name in the House of Commons of Canada[13] and the Legislative Assembly of Quebec.

[14] This article incorporates text from this source, which is in the public domain: "Proclamation, March 4, 1841", Journals of the Legislative Council of the Province of Canada, 1st Parliament, 1st Session, 1841, p. xiv.