An Unlikely Union tells the dramatic story of how two of America’s largest ethnic groups learned to love and laugh with each other after decades of animosity. They came from the poorest parts of Ireland and Italy and met as rivals on the sidewalks of New York. Beginning in the nineteenth century, the Irish and Italians clashed in the Catholic Church, on the waterfront, at construction sites, and in the streets. Then they made peace through romance, marrying each other on a large scale in the years after World War II.