We were bringing in 250,00 to 300,000 a year from 1924 to 1965. Then the Immigration Act of 1965 was passed to make the population of the US look more like the rest of the world. It was part of the Civil Rights movement and really wasn't caused by Catholics.
The American left has always promoted Catholic immigration, just as they are in modern times, for instance the 1965 bill.
“However, if there is one man who can take the most credit for the 1965 act, it is John F. Kennedy. Kennedy seems to have inherited the resentment his father Joseph felt as an outsider in Boston’s WASP aristocracy. He voted against the McCarran-Walter Act of 1952, and supported various refugee acts throughout the 1950s.
In 1958 he wrote a book, A Nation of Immigrants, which attacked the quota system as illogical and without purpose, and the book served as Kennedy’s blueprint for immigration reform after he became president in 1960. In the summer of 1963, Kennedy sent Congress a proposal calling for the elimination of the national origins quota system. He wanted immigrants admitted on the basis of family reunification and needed skills, without regard to national origin. After his assassination in November, his brother Robert took up the cause of immigration reform, calling it JFK’s legacy. In the forward to a revised edition of A Nation of Immigrants, issued in 1964 to gain support for the new law, he wrote, “I know of no cause which President Kennedy championed more warmly than the improvement of our immigration policies.” Sold as a memorial to JFK, there was very little opposition to what became known as the Immigration Act of 1965.”