Thesis advisor: André Brouillette / Thesis advisor: Maura Jane Farrelly / The purpose of this thesis is to better understand American colonial Catholicism through a comparative study of it with Catholicism in colonial Canada, both before and after the British defeat of the French in 1759, in the period of the American Revolution. Despite a shared faith, ecclesiastical leaders in Canada were wary of the revolutionary spirit and movement in the American colonies, participated in by American Catholics, and urged loyalty to the British crown. The central question of the study is as follows: why did the two groups, American Catholics (the Maryland Tradition) and Canadian Catholics (the Quebec Tradition), react so differently to British colonial rule in the mid eighteenth-century? Developing an understanding of the religious identities of American and Canadian Catholics and their interaction during the period will help shed light on their different approaches to political ideals of the Enlightenment and their Catholic faith / Thesis (STL) — Boston College, 2017. / Submitted to: Boston College. School of Theology and Ministry. / Discipline: Sacred Theology.