With the vast numbers of German and Irish coming to America, hostility to them erupted. Part of the reason for the opposition was religious. All of the Irish and many of the Germans were Roman Catholic. Part of the opposition was political. Most immigrants living in cities became Democrats because the party focused on the needs of commoners. Part of the opposition occurred because Americans in low-paying jobs were threatened and sometimes replaced by groups willing to work for almost nothing in order to survive. Signs that read "NO IRISH NEED APPLY" sprang up throughout the country.

Ethnic and ANTI-CATHOLIC RIOTING occurred in many northern cities, the largest occurring in Philadelphia in 1844 during a period of economic depression. Protestants, Catholics and local militia fought in the streets. 16 were killed, dozens were injured and over 40 buildings were demolished. "NATIVIST" political parties sprang up almost overnight. The most influential of these parties, the KNOW NOTHINGS, was anti-Catholic and wanted to extend the amount of time it took immigrants to become citizens and voters. They also wanted to prevent foreign-born people from ever holding public office. Economic recovery after the 1844 depression reduced the number of serious confrontations for a time, as the country seemed to be able to use all the labor it could get.

Why were so many Irish immigrants disliked by Americans? (2 reasons)

The Irish immigrants were disliked by Americans for two main reasons: religious differences and competition for jobs. The Irish were Roman Catholic, which was seen as a threat by the Protestant majority in America. Additionally, the Irish were willing to work for very low wages, threatening the jobs of Americans already living there.