During the dreadful famine summer of 1847, as thousands of indigent Irish streamed from floating coffin ships to meet their fate in the cities and countryside of British North America, growing number of people vociferously expressed fears that had been simmering for well over decade. Disquieted members of Canada's House of Assembly, for example, unanimously agreed to address Queen Victoria with their apprehensions concerning the unprecedented influx of Emigrants from Great Britain and Ireland in state of destitution, starvation, and disease, unparalleled in the history of this province. [1] Genuine concern for the condition of the immigrants was swiftly tempered, and then virtually disappeared, as native-born and immigrant Protestants considered the possible ramifications that the accelerated introduction of large numbers of Irish Catholics would have on British North American society. Within decade, the same Toronto newspaper that had once greeted the famine migration with humanitarian appeals for aid had hardened its opinion into nativist resolve to bar further Irish-Catholic emigration entirely. In response to news from the United States that thousands of unenlightened and bigoted Romanists might slip northward across the border, the Globe predicted a great calamity, dangerous to our civil and religious liberty, calamity which every true patriot, Protestant as well as Roman Catholic, should endeavour, by all means in his power, to avert. [2] The first clear episode of nativism--the emphatic rejection of immigrants because of their foreign identification--in pre-Confederation Canadian history was triggered by the events of the late 1840s. Strikingly, this response to the famine Irish, which was fueled by mixture of Protestant anxiety over the global spread of Roman Catholicism and an antipathy to Celtic peoples, has to date received little historiographical attention. [3] Yet the Canadian experience coincided with nativism in the United States, more widely recognized phenomenon that became an integral component of nationalism and political-party formation. Canada's nativism may even have matched America's in fervor during the mid-nineteenth century, although its manifestations were certainly different. This study seeks to identify and explain the nativist response to the famine Irish who made their way to Canada. British North American nativism was complex and varied, depending on economic, demographic, and social themes in various provinces, yet its disparate elements may be characterized by several interrelated themes. The first might be understood as critical mass dynamic, which suggests that dramatic number of Irish-Catholic immigrants rapidly surpassed an acceptable threshold when they settled among or near native-born and immigrant Protestants. The international context of anti-Catholicism, pervasive impulse in the Western world of the nineteenth century, represents another basic principle at work. The third addresses chronology, suggesting confluence of events as this immigrant cohort altered and was in turn shaped by British North America's political, economic, and social landscapes. Nativism was one of the tremors that rippled across North America as powerful ethnoreligious plates collid ed in the mid-nineteenth century. This event will be best understood by first considering the theoretical and historiographical contexts of and then by focusing on the themes just described. Nativism has been recurrent social and political force in the last two centuries of American history. John Higham, who concentrated his energies on American movements, defined nativism as the intense opposition to an internal minority on the ground of its foreign... connections, or defensive type of nationalism. Though Higham cautioned that the word nativism, of nineteenth-century derivation, over time assumed pejorative connotations, his definition provides durable intellectual device for analyzing host population's reaction to immigrants. …