At the turn of the 19th century, the majority of Ireland's land was owned by the English, who rented it in small plots to Irish farmers. Without the capital to purchase modern equipment or adopt advanced agricultural methods, Irish farm laborers earned eight pence a day, about a fifth of what could be obtained in the New World. In 1816, approximately 6,000 Irish sailed for America; two years later, the number had doubled.

In October 1845, about 75 percent of Ireland's potato crop was devastated when a serious blight hit the country. As the principal food for over four million people, The Great Potato Famine led to the death of nearly 1 million people over the next five years. The Irish people blamed the British government and absentee landlords for the catastrophe, and the famine ignited a newfound desire to emigrate to America. By 1855, nearly one million Irish-a quarter of the country's population-had emigrated to the United States.

Life in America proved difficult for the Irish immigrants, the vast majority of whom lived in desperate poverty near the ports where they had disembarked. Unwanted and unwelcome, the Irish clung to their Catholic faith and often resorted to physical violence in the face of severe discrimination. Desperation forced them to take the country's most dangerous jobs, including building bridges, canals and railroads. The Irish also met deplorable conditions while working in coal mines, eventually organizing a secret society called the Molly Maguires to intimidate mine owners.

During the Civil War, the Union Army had four times the number of Irish as the Confederates, but in general the Irish lacked sympathy for the slaves, believing emancipation would threaten their jobs. After the war, large Irish populations in cities like Boston, New York and Chicago enabled Irish voters to get their candidates elected to power. The number of Irish in the police force and fire departments also swelled. This, combined with an influx of new immigrant Jews, Slavs, and Italians, turned the tide for the Irish in America.

By 1900, living conditions had improved and institutionalized discrimination had waned for the majority of Irish Americans. Their contribution to American culture, education, politics, science and business during the 20th century is immeasurable. From the depths of discrimination to the heights of the oval office, the Irish have woven an intricate and proud path through the fabric of American history. Read about the contributions of some of the country's most notable Irish Americans.