How were Jews viewed in the United States in the pre-WWII era?
The best I can say is that the Jews were tolerated in the U.S. before WWII.
Most social clubs refused to admit them as members. Colleges and universities often had a quota system which permitted only a small percentage of students in their student bodies.
Even in 1951, these ideas were still prevalent. I belonged to a national college sorority then. One girl wanted to join, but the members voted not to accept her because she "looked Jewish."
Read this article for more information.
http://en.wikipedia.org/wiki/History_of_the_Jews_in_the_United_States