Final answer:
The American Protective Association was an anti-Catholic and anti-immigrant organization in the late nineteenth century with over half a million members. The correct answer is option 1.
Step-by-step explanation:
The late nineteenth century anti-Catholic organization with over 500,000 members was the American Protective Association. This group was formed in 1887, mainly opposing immigrants from central and southern Europe, as well as Jewish and Catholic migrants. Its campaigns and political lobbying were significant in the enactment of the Chinese Exclusion Act and laid the groundwork for several immigration restriction acts in the early 20th century, including the Emergency Quota Act of 1921 and the Immigration Act of 1924.