Answer;
The American party, also known as the Know-Nothing Party, encouraged immigration reforms to prevent the arrival to the USA of Catholic Immigrants
Other reasons they gave to encourage the reforms include;
-Immigrants were stealing jobs from "true Americans"
-Catholic church opposed taxation to give funds to public schools.
-Catholics were loyal to the Pope, instead of being loyal to the USA.
-Most of the immigrants were poor peasants who caused the crime rates to grow.