The term "American Party" can refer to several political movements in U.S. history, but it is most commonly associated with the Know Nothing Party of the 1850s. This party emerged in response to the increasing immigration of Irish and German Catholics, promoting nativist policies and advocating for the interests of native-born Americans. Another notable American Party is the American Party founded in 1969, which aimed to address issues like civil rights and government reform. This party sought to unite various conservative factions but struggled to gain significant traction in the political landscape.