Immigration from non-European countries increased dramatically. The act removed de facto discrimination against Southern and Eastern Europeans, Asians, and other non-Northwestern European ethnic groups from American immigration policy. The highest number of immigrants (4.3 million) to the U.S. came from Mexico, in addition to some 1.4 million from the Philippines. Korea, the Dominican Republic, India, Cuba and Vietnam were also leading sources of immigrants, each sending between 700,000 and 800,000 over this period.
Explanation: the underground railroad was there to help the slaves escape to freedom. They only traveled at night and stayed at people who supported them being free´s homes. Most people did not care if they got caught because no matter what they did they would get in trouble.