经过数次立宪会议之后，1867年宪法法案于1867年7月1日通过，加拿大省、新不伦瑞克省、新斯科舍省三个英属北美殖民地组成加拿大联邦。加拿大获得罗伯特领地和西北部地区的控制权，并将两者合并成西北地区，这一举动促使该地区的原住民梅蒂人在1870年7月发动红河起义并建立从西北地区分离出的马尼托巴省。
1871年，不列颠哥伦比亚省（不列颠哥伦比亚殖民地与温哥华岛殖民地已在1866年合并）加入联邦。两年后，爱德华王子岛也加入联邦。
首任总理约翰·亚历山大·麦克唐纳及他的保守党政府设立关税以保护加拿大新生的制造业。为了开发西部，加拿大政府资助三项横加铁路项目（包括加拿大太平洋铁路），并配合自治领土地法 ，开始对大平原的开发。为了维护这片新开发区域的治安，加拿大政府设立西北山地警察局。1898年掀起的克朗代克淘金热为加拿大西北领地带来大批移民，这一事件直接促使这片区域从西北领地分离并建立育空地区。在加拿大自由党的总理威尔弗里德·劳雷尔的领导下，欧洲移民开始在大平原地区定居，因此促成艾伯塔省和萨斯喀彻温省在1905年建立。
Following several constitutional conferences, the Constitution Act officially proclaimed Canadian Confederation on July 1, 1867, initially with four provinces: Ontario, Quebec, Nova Scotia, and New Brunswick. Canada assumed control of Rupert's Land and the North-Western Territory to form the Northwest Territories, where the Métis' grievances ignited the Red River Rebellion and the creation of the province of Manitoba in July 1870. British Columbia and Vancouver Island (which had been united in 1866) joined the confederation in 1871, while Prince Edward Island joined in 1873. In 1898, during the Klondike Gold Rush in the Northwest Territories, parliament created the Yukon Territory. Alberta and Saskatchewan became provinces in 1905. Between 1871 and 1896, almost one quarter of the Canadian population emigrated southwards, to the U.S.
To open the West and encourage European immigration, Parliament approved sponsoring the construction of three transcontinental railways (including the Canadian Pacific Railway), opening the prairies to settlement with the Dominion Lands Act, and establishing the North-West Mounted Police to assert its authority over this territory. This period of westward expansion and nation building resulted in the displacement of many Indigenous peoples of the Canadian Prairies to "Indian reserves", clearing the way for ethnic European block settlements. This caused the collapse of the Plains Bison in western Canada and the introduction of European cattle farms and wheat fields dominating the land. The Indigenous peoples saw widespread famine and disease due to the loss of the bison and their traditional hunting lands The federal government did provide emergency relief, on condition of the Indigenous peoples moving to the reserves. During this time, Canada introduced the Indian Act extending its control over the First Nations to education, government and legal rights.