Irish Canadians are Canadian citizens of Irish descent, including descendants who trace their ancestry to immigrants who originated in Ireland. 1.2 million Irish immigrants arrived from 1825 to 1970, and at least half of those in the period from 1831–1850. By 1867, they were the second largest ethnic group (after the French), and comprised 24% of Canada's population. The 1931 national census counted 1,230,000 Canadians of Irish descent, half of whom lived in Ontario. About one-third were Catholic in 1931 and two-thirds Protestant.