Immigration was a high priority topic in American politics during Wilson's presidency, but he gave the matter little attention. Wilson's progressivism encouraged his belief that immigrants from Southern and Eastern Europe, though often poor and illiterate, could assimilate into a homogeneous white middle class, and he opposed the restrictive immigration policies that many members of both parties favored. Wilson vetoed the Immigration Act of 1917, but Congress overrode the veto. The act's goal was to reduce immigration from Eastern and Southern Europe by requiring literacy tests, and it was the first U.S. law to restrict immigration from Europe.