"When many think of Irish emigration, they think of potato blight and the Great Famine of the 1840s, which caused so many to flee Ireland for the U.S. But the real history of the Irish diaspora is much longer, more complicated, and more global. Starting in the 17th century, Irish clerics, mercenaries, and merchants began to fan out across America, Canada, Australia, and New Zealand, setting in motion a pattern of migration that would play an essential...