In the 1930's many countries refused to accept Jewish refugees because immigration quotas had already been

They refused to accept Jews because they had already been filled

Immigration quotas had already been filled.

The United States was one of those countries. As noted by Facing History and Ourselves: "Like most other countries, the United States did not welcome Jewish refugees from Europe." The vast majority of Americans were opposed to the admission of refugees. They feared it as a national security issue and thought it would have a negative impact on the economy and jobs. (Remember that the USA was still working its way out of the Depression.)