Which of the following was one of the reasons Catholics faced discrimination from Protestants in the United States during the 19th century? A. Protestants felt that Catholics were too tolerant of African Americans, Jews, and Mormons. B. Protestants feared that Catholics would be loyal to the Pope and that foreign influence would control American politics. C. Catholic immigrants were often quite wealthy, and Protestants felt threatened by their potential to displace them in upper-class society. D. Catholics actively pursued legislation to end the separation of church and state and to establish Catholicism as the national religion.

B. Protestants feared that Catholics would be loyal to the Pope and that foreign influence would control American politics.

Explanation: During the 19th century, there was a significant increase in Catholic immigration to the United States, particularly from countries like Ireland, Italy, and Germany. In this period, the majority of Americans were Protestant and of English, Scottish, or Dutch heritage, and they were suspicious of these new arrivals, who were culturally and religiously different.

Protestant Americans of the time were worried that Catholics, because of their allegiance to the Pope, would not integrate into the democratic values of the country and would be more loyal to a foreign religious authority than to the US government. This anxiety over a divided loyalty was a major source of anti-Catholic sentiment and led to discrimination, social prejudice, and sometimes even violent confrontations. This sentiment was also fueled by the cultural and religious differences between the predominantly Protestant society and the Catholic newcomers.