From Ohio History Central
The Know-Nothing Party, also known as the American Party, was a prominent United States political party during the late 1840s and the early 1850s.
The American Party originated in 1849. Its members strongly opposed immigrants and followers of the Catholic Church. The majority of white Americans followed Protestant faiths. Many of these people feared Catholics because members of this faith followed the teachings of the Pope. The Know-Nothings feared that the Catholics were more loyal to the Pope than to the United States. More radical members of the Know-Nothing Party believed that the Catholics intended to take over the United States of America. The Catholics would then place the nation under the Pope's rule. The Know-Nothing Party intended to prevent Catholics and immigrants from being elected to political offices. Its members also hoped to deny these people jobs in the private sector, arguing that the nation's business owners needed to employ true Americans.