When Lawrence J. McCaffrey's The Irish Diaspora in America was published in 1976, it won rave reviews and quickly became the standard college and university text on the Irish-American experience. Named the "best short history of the Irish in America" by Andrew M. Greeley in a New York Times review, McCaffrey's work traced the experience of Irish-American Catholics from their beginnings as detested, unskilled pioneers of the urban ghetto to their rise...