the popular name for the American Republican Party, later called the American Party, which was established in 1843 with the aim of restricting immigration and preventing Roman Catholics from holding public office. They were called Know-Nothings because members of the party were told to say 'I know nothing' when asked about it. They were also called 'nativists' because they believed that foreign-born Americans should not be allowed to hold government posts. They had some success in the 1850s, but were divided over the issue of slaves, and the party soon came to an end. The word know-nothing is still sometimes applied in the US to a person with political views which are too fixed and not reasonable.