The Know Nothing movement was a
nativist American political movement of the
1850s. It was empowered by popular fears that the country was being overwhelmed by
Irish Catholic immigrants, who were often regarded as hostile to American values and controlled by the
Pope in Rome. Mainly active from 1854–56, it strove to curb immigration and
naturalization, though its efforts met with little success. There were few prominent leaders, and the largely middle-class and Protestant membership fragmented over the issue of slavery, most often joining the
Republican Party by the time of the
1860 presidential election.
See more at Wikipedia.org...