Answer:
"was dedicated to reserving political office for native-born Americans."
Explanation:
The Know-Nothing Party, also known as the American Party, was a nativist political movement in the mid-19th century United States. They opposed immigration and the growing political influence of Catholic immigrants, particularly the Irish.
Here's why the other answer choices are not the best fit:
prevented foreign-born people from voting after 1860: While they did advocate for restrictions on immigration and voting rights for immigrants, the Know-Nothing Party largely faded by 1860.
supported slavery: The Know-Nothing Party wasn't a strong advocate for or against slavery. Their primary focus was on nativism and anti-Catholicism.
supported equal political rights for all religious groups: The Know-Nothing Party specifically targeted Catholics, not advocating for equal rights for all religions.
opposed the temperance movement: The temperance movement aimed to limit alcohol consumption, and there's no clear evidence the Know-Nothing Party strongly opposed it.