Xenophobic and anti-Catholic American political party, active in the 1850s.
The "Know Nothing Party" arose as the result of division within the ranks of the established parties on the slavery/abolition issue, and drew its core membership from various secret societies and lodges in New York state. Members were schooled to respond to direct questioning with the statement: "I know nothing". Several official names for the party existed, among these "The American Party".
In 1856, former President Millard Fillmore ran for election as the presidential candidate of the party, but suffered a notable defeat at the polls. Following this, the party soon disintegrated - however, it is often considered a precursor of other right-wing extremist movements in the U.S.A., such as the Ku Klux Klan.