“When Irish Eyes Are Smiling” was written in 1912. By that time, the Irish immigrants who had come to the United States in the 1800s with few skills and little education had managed to transform their place in America. They had carved out a middling working-class profile in American society and established real political power in many Northeastern cities.
To a large extent, the evolution of America’s Irish population went hand in hand with the evolution of the cities in which they lived. As these cities grew and were forced to expand the services essential to urban life, Irish workers filled and, in many cases, monopolized these services. They eventually held a disproportionate share of all positions in the growing fire and police departments, and they dominated several construction industries and crafts. At a time when Irish American workers represented about 7% of all male workers, they represented more than 30% of all plumbers, steamfitters, and boilermakers.
Irish Americans also wielded considerable political power by 1900. In cities like New York, where by 1885 they represented 40% of the total population, their sheer numbers guaranteed that their voice would be heard. They also built powerful political organizations. The most prominent of these was Tammany Hall, a political machine that dominated New York politics for roughly 60 years around the turn of the century.