In the United States, he achieved prominence in Irish-American circles and founded and edited the New York-based
Nation and the Boston-based
American Celt. He also wrote a number of history books. In common with several other Young Ireland
émigrés, McGee espoused
proslavery thought and defended the continuation of
slavery in the United States. In the 4 August 1849 edition of the
Nation, McGee attacked supporters of the abolitionist
Daniel O'Connell in the United States, writing that "Their task is to liberate their slaves, not to travel across the Atlantic for foreign objects of sympathy." McGee eventually grew disillusioned with democracy,
republicanism and the United States. Historian David Gerber traces a dramatic transformation from the
Young Ireland revolutionary who sought a peasant rebellion to overthrow British rule in Ireland. Gerber writes: :After 1851, however, he veered increasingly toward the opposite pole, espousing an
ultramontane conservatism.... Catholic dogma and triumphalism, anti-Protestantism, cultural nationalism, and
social conservatism were the framework of McGee's thought during the 1850s. He emigrated to Montreal in 1857, believing Canada was far more hospitable to the Catholic Irish than was the United States. He downplayed the importance of the
Orange Order in Canada. He remained a persistent critic of American institutions, and of the American way of life. He accused the Americans of hostile and expansionist motives toward Canada and of desiring to spread its republican ideas over all of North America. McGee worked energetically for continued Canadian devotion to the
British Empire, seeing it as necessary to protect Canada from American influence. ==Canada==