The growing immigrant population in the United States led to the creation of the Know-Nothing Party
Explanation:
The native people who were against the immigration were started a secret society. And slowly this secret society movement started spreading their ideology of Know Nothing movement.
This movement was the called Nativist political party who were active in the mid 1850’s and they were active throughout America. In the year 1955 the Native American party then on called them as American Party and also known by their ideology Know Nothing movement.
Their main goal is to keep power with native born American citizens and stopped immigrants and Catholics beings elected to public offices.