Suddenly, in the mid-1840s, the size and nature of Irish immigration changed drastically. The potato blight which destroyed the staple of the Irish diet produced famine. Hundreds of thousands of peasants were driven from their cottages and forced to emigrate -- most often to North America. Unlike the earlier migration, these people had no skills, no previous experience in adapting to a new country. They also had no money, few clothes, and very little hope. Most had no education. Further, despite a fierce loyalty to the Catholic Church, most had had little formal religious training. Catholicism had only been legalized a dozen years earlier.
Contribution to U.S. Economic Expansion * The growing economy of the United States in the early 1800s needed all the working hands available. Railway expansions, canals, as well as factories would be unable to work in full swing without the newcomers from abroad. Unemployment and poverty were something Irish immigrants were willing to avoid at all costs, so they undertook any available labor job, no matter how intensive and harsh it was. Their hard work contributed to the rapid economic growth of the country during the better part of the 19th century.
Spread of Catholicism * Immigrants from Ireland brought with them their Catholic faith. New Catholic churches were established in places where Irish were settled, such as Illinois Valley and New York City. According to the U.S. Catholic magazine, in 1820, Catholics were the smallest denomination in the United States, with 195,000 members. By 1860, they were the largest, rising to 3.1 million. New customs were introduced, as well; a common example is St. Patrick's Day, for which nowadays even the White House fountain is dyed green on March 17.
Urban Expansion * Newcomers from Ireland were too poor to buy their own land or at least find stable employment which would allow them to live in comfortable conditions. Instead, Irish immigrant families had to gather in the cheap accommodations urban centers provided, such as small, crumbling houses and cellars. This led to the inevitable expansion of the urban centers, primarily in the northeast states, contributing in a way to the bustling cities of today.
Rows and Riots * Settling in their new land was not an easy process for the Irish immigrants. In addition to their hardships, they had to cope with the English-American discomfort. The reasons for this sentiment was both religious (English-Americans were predominantly Protestants), as well as political, orchestrated by nativist organizations, including the "Know Nothing" movement. Discomfort grew to outright animosity on occasions, such as the Philadelphia nativist riots of 1844. * Nativists launched a sustained attack on Irish immigrants because of their Catholicism. In 1834 a mob burned down the Ursuline convent in…