Movement from Ireland to the United States continued into the nineteenth century and began to increase in response to new opportunities. Notably, the U.S. began to build up its first transportation infrastructure, in the form of canals. The Erie Canal in New York State, perhaps the best known of these waterways, was under construction from 1818 to 1825. That project drew heavily on immigrant Irish labor, beginning the long history of building the American transportation infrastructure with Irish workers. The success of the Erie Canal stimulated the digging of canals in other parts of the country, creating a growing demand for workers who were willing to endure the hard labor required in canal building. Somewhat later, the Illinois & Michigan Canal, created between 1837 and 1848, employed hundreds of Irish laborers. To the south, Irish workers dug the canal system of swampy New Orleans.
Reliable data on how many Irish reached American shores date only from 1820. In 1819, the United States passed the Steerage Act. It gave the U.S. government information on immigration by requiring that all vessels reaching American shores deliver passenger lists to customs officials, who then sent copies to the U.S. State Department. That department would, in turn, submit the lists to Congress. As a result, 1820 became the first year in which the U.S. systematically collected data on new arrivals. During that same year, the Irish made up the single largest immigrant group, accounting for 43 percent of all arrivals to the United States.
Irish immigration continued at high levels throughout the decades leading up to the Civil War. The numbers of Irish immigrants rose from 51,617 during the 1820’s to 170,672 during the 1830’s, increasing still further to 656,145 during the 1840’s. During the decade of the 1850’s, the number of people arriving in the United States from Ireland reached its historical peak at 1,029,486.
One reason that the flow fromIreland increased during these years was that the demand for their labor continued to rise. The railroads made up the second major part of the American transportation system, after the canals. In 1830, the United States had only 23 miles of railroad. Only one decade later, this figure had grown to 2,818 miles. It increased to 9,021 miles in 1850 and then to 30,626 miles in 1860. Immigrants fromIreland, in particular, laid these miles of tracks.
The Irish were also pushed out of their native land by poverty and hunger as the middle of the century approached. The Potato Blight created famine in Ireland in the years 1845 to 1850. Continuing hardship, in addition to the existence of established Irish communities around the United States, pushed immigration from Ireland to its record level in the 1850’s.
By the middle of the nineteenth century, Irish Americans were an urban and working class group. Only 16 percent of people born in Ireland lived on farms in the United States in 1850, compared to well over one-half of all Americans. A majority of the Irish in the United States (53 percent) lived in urban areas, at a time when urban areas were home to only 15 percent of the people in the nation. While only about 15 percent of all workers in the country were listed as laborers by occupation, about half the Irish natives in the census of that 1850 were so identified.
Anti-Irish feeling among other groups in the United States resulted, in part, fromthe concentration of many Irish immigrants in lower-income districts of cities, which caused the Irish to be associated with urban slums. Prejudice against this group also resulted from religious differences. Most Irish immigrants who arrived after 1830 were Roman Catholics. The established population of the United States was mainly Protestant. Suspicion of Catholics in general and of Irish Catholics in particular led to the creation of a number of anti-Catholic organizations. The Native American Party, later renamed the American Party and popularly known as the “Know-Nothing” Party, was the most prominent of these. Fear that floods of Catholics from Ireland and other locations threatened to overwhelm the native-born, Protestant population produced widespread victories for this anti-immigrant and anti- Catholic party in elections across the nation in 1855 and 1856.