The Native American Party, renamed the American Party in 1855 and commonly known as the Know-Nothing movement, was an American nativist political party that operated countrywide in the mid-1850s. It was primarily anti-Catholic and nativist, starting originally as a secret society, the Order of the Star Spangled Banner. The movement briefly emerged as a major political party in the form of the American Party. Adherents to the movement were to reply "I know nothing" when asked about its specifics by outsiders, thus providing the group with its common name.
The term has more recently become a provocative slur, suggesting that the opponent is both nativist and ignorant.